Update references to ref fields spec (#64686)

Author: cston

src/Compilers/CSharp/Portable/Binder/Binder_Statements.cs

@@ -1542,11 +1542,10 @@ private BoundAssignmentOperator BindAssignment(
                 {
                     if (isRef)
                     {
-                        // https://github.com/dotnet/csharplang/blob/main/proposals/low-level-struct-improvements.md#rules-ref-reassignment
-                        // For a ref reassignment in the form ...
-                        // 1. x.e1 = ref e2: where x is safe-to-escape at least return only then e2 must have ref-safe-to-escape at least as large as x
-                        // 2. e1 = ref e2: where e1 is a ref local or ref parameter then e2 must have a safe-to-escape equal to safe-to-escape for e1 and
-                        //    e2 must have ref-safe-to-escape at least as large as ref-safe-to-escape of the ref-safe-to-escape of e1
+                        // https://github.com/dotnet/csharplang/blob/main/proposals/csharp-11.0/low-level-struct-improvements.md#rules-ref-reassignment
+                        // For a ref reassignment in the form `e1 = ref e2` both of the following must be true:
+                        // 1. `e2` must have *ref-safe-to-escape* at least as large as the *ref-safe-to-escape* of `e1`
+                        // 2. `e1` must have the same *safe-to-escape* as `e2`
 
                         var leftEscape = GetRefEscape(op1, LocalScopeDepth);
                         var rightEscape = GetRefEscape(op2, LocalScopeDepth);

src/Compilers/CSharp/Portable/Symbols/Source/SourceLocalSymbol.cs

@@ -111,7 +111,7 @@ internal override SyntaxNode ScopeDesignatorOpt
             get { return _scopeBinder.ScopeDesignator; }
         }
 
-        // From https://github.com/dotnet/csharplang/blob/main/proposals/low-level-struct-improvements.md:
+        // From https://github.com/dotnet/csharplang/blob/main/csharp-11.0/proposals/low-level-struct-improvements.md:
         //
         // | Parameter or Local     | ref-safe-to-escape | safe-to-escape |
         // |------------------------|--------------------|----------------|

src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberContainerSymbol_ImplementationChecks.cs

@@ -1383,7 +1383,7 @@ internal static bool RequiresValidScopedOverrideForRefSafety(MethodSymbol? metho
 
             var parameters = method.Parameters;
 
-            // https://github.com/dotnet/csharplang/blob/main/proposals/low-level-struct-improvements.md#scoped-mismatch
+            // https://github.com/dotnet/csharplang/blob/main/proposals/csharp-11.0/low-level-struct-improvements.md#scoped-mismatch
             // The compiler will report a diagnostic for _unsafe scoped mismatches_ across overrides, interface implementations, and delegate conversions when:
             // - The method returns a `ref struct` or returns a `ref` or `ref readonly`, or the method has a `ref` or `out` parameter of `ref struct` type, and
             // ...
@@ -1422,7 +1422,7 @@ internal static bool RequiresValidScopedOverrideForRefSafety(MethodSymbol? metho
         /// </summary>
         internal static bool ReportInvalidScopedOverrideAsError(MethodSymbol baseMethod, MethodSymbol overrideMethod)
         {
-            // https://github.com/dotnet/csharplang/blob/main/proposals/low-level-struct-improvements.md#scoped-mismatch
+            // https://github.com/dotnet/csharplang/blob/main/proposals/csharp-11.0/low-level-struct-improvements.md#scoped-mismatch
             // The diagnostic is reported as an error if the mismatched signatures are both using C#11 ref safety rules; otherwise, the diagnostic is a warning.
             return baseMethod.UseUpdatedEscapeRules && overrideMethod.UseUpdatedEscapeRules;
         }

src/Compilers/CSharp/Test/Semantic/Semantics/RefFieldTests.cs

@@ -8350,12 +8350,12 @@ static R2 F4(ref int i)
             else
             {
                 comp.VerifyEmitDiagnostics(
-                // (16,16): error CS8352: Cannot use variable 'y1' in this context because it may expose referenced variables outside of their declaration scope
-                //         return y1; // 1
-                Diagnostic(ErrorCode.ERR_EscapeVariable, "y1").WithArguments("y1").WithLocation(16, 16),
-                // (23,16): error CS8352: Cannot use variable 'y2' in this context because it may expose referenced variables outside of their declaration scope
-                //         return y2; // 2
-                Diagnostic(ErrorCode.ERR_EscapeVariable, "y2").WithArguments("y2").WithLocation(23, 16));
+                    // (16,16): error CS8352: Cannot use variable 'y1' in this context because it may expose referenced variables outside of their declaration scope
+                    //         return y1; // 1
+                    Diagnostic(ErrorCode.ERR_EscapeVariable, "y1").WithArguments("y1").WithLocation(16, 16),
+                    // (23,16): error CS8352: Cannot use variable 'y2' in this context because it may expose referenced variables outside of their declaration scope
+                    //         return y2; // 2
+                    Diagnostic(ErrorCode.ERR_EscapeVariable, "y2").WithArguments("y2").WithLocation(23, 16));
             }
         }