Fix 3016: Decode syntactic types using FSharpFunc, Tuple, ValueTuple

[dsyme]

Tentative fix for #3016

Basically if the user code contains System.ValueTuple<int,int> then we treat that exactly as if struct (int * int) has been written. The compiler uses this form until emit. We were already doing this for types coming from C# assemblies but not for types written in F# code. We apply to FSharpFunc, Tuple and ValueTuple

[dsyme]

Errors that need fixing:

1) Failed : FSharp-Tests-Core+TypecheckTests.sigs pos27
Error running command 'D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\..\..\release\net40\bin\fsc.exe' with args '-r:System.Core.dll --nowarn:20 --define:COMPILED --target:exe -o:pos27.exe pos27.fs' in directory 'D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs'. ERRORLEVEL 1
at TestFramework.checkResult(CmdResult result) in D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\test-framework.fs:line 259
at TestFramework.exec@438-22.Invoke(CmdResult result) in D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\test-framework.fs:line 438
at TestFramework.fsc@446-1.Invoke(String flags, FSharpList`1 srcFiles) in D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\test-framework.fs:line 446
at FSharp-Tests-Core.TypecheckTests.sigs pos27() in D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\tests.fs:line 1678

2) Error : FSharp-Tests-Core+TypecheckTests.type check neg23
System.Exception : neg23.err neg23.bsl differ; "diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.err]
line 2
 - neg23.fs(9,21,9,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(9,21,9,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.err]
line 4
 - neg23.fs(7,21,7,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(7,21,7,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.err]
line 6
 - neg23.fs(19,21,19,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(19,21,19,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.err]
line 8
 - neg23.fs(17,21,17,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(17,21,17,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.err]
line 10
 - neg23.fs(28,21,28,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(28,21,28,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.err]
line 12
 - neg23.fs(26,21,26,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(26,21,26,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass'.
"; neg23.vserr neg23.bsl differ; "diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.vserr]
line 2
 - neg23.fs(9,21,9,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(9,21,9,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.vserr]
line 4
 - neg23.fs(7,21,7,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(7,21,7,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure1.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.vserr]
line 6
 - neg23.fs(19,21,19,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(19,21,19,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.vserr]
line 8
 - neg23.fs(17,21,17,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(17,21,17,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure2.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.vserr]
line 10
 - neg23.fs(28,21,28,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(28,21,28,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass'.
diff between [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.bsl] and [D:\j\workspace\release_ci_pa---866fd2c3\tests\fsharp\typecheck\sigs\neg23.vserr]
line 12
 - neg23.fs(26,21,26,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass' once tuples, functions, units of measure and/or provided types are erased.
 + neg23.fs(26,21,26,24): typecheck error FS0438: Duplicate method. The method 'Foo' has the same name and signature as another method in type 'DuplicateOverloadUpToErasure3.SomeClass'.
"
   at Microsoft.FSharp.Core.PrintfModule.PrintFormatToStringThenFail@1379.Invoke(String message) in D:\j\workspace\release_ci_pa---866fd2c3\src\fsharp\FSharp.Core\printf.fs:line 1379

[dsyme]

@dotnet-bot test Windows_NT Release_ci_part1 Build please

[dsyme]

This is ready

[dsyme]

A very belated RFC for this breaking change is at https://github.com/fsharp/fslang-design/blob/master/FSharp-4.1b/FS-1046-consistent-tuple-types.md

[cartermp]

Thanks!