Empty Main works for corerun on WASM

[AaronRobinsonMSFT]

Implement array allocators for WASM.

Calling empty Main() works for corerun. Steps:

1. Build coreclr and libs for browser
   • ./build.sh -os browser -c Debug -subset clr.runtime+libs
   • It is okay if the "libs" build fails. We just need System.Runtime.dll to build.
2. Copy over System.Runtime.dll to the IL location containing System.Private.CoreLib.dll
3. Build a simple C# application:

   public static class Program
   {
       public static void Main() { }
   }

4. Copy the simple C# application to the IL location. It should now have System.Private.CoreLib.dll, System.Runtime.dll and <app>.dll.

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[Copilot]

Pull Request Overview

This PR implements essential array allocation functionality for WebAssembly (WASM) to enable empty Main() method execution in corerun. The implementation provides basic memory allocation, method invocation infrastructure, and interpreter support necessary for minimal CLR functionality on WASM.

Key changes include:

• Implementation of array allocation helpers (RhpNewArrayFast, RhNewString) to support basic object creation
• Addition of managed method invocation support through portable entry points and call stubs
• Updates to method compilation and invocation infrastructure for WASM interpreter compatibility

Reviewed Changes

Copilot reviewed 22 out of 23 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/coreclr/vm/wasm/helpers.cpp	Implements calli stubs and managed method invocation for WASM interpreter
src/coreclr/vm/threads.cpp	Fixes preprocessor directive placement for portable helpers
src/coreclr/vm/runtimehandles.cpp	Adds null check assertion for type handle validation
src/coreclr/vm/prestub.cpp	Enhances FCall handling with portable entry point support and managed implementation detection
src/coreclr/vm/precode_portable.hpp	Adds method for creating portable entry points from native code
src/coreclr/vm/precode_portable.cpp	Implements portable entry point creation and code address management
src/coreclr/vm/portable/AllocSlow.cpp	Adds allocation failure handler stub
src/coreclr/vm/object.h	Adds SetNumComponents method and removes unused friend declarations
src/coreclr/vm/method.cpp	Refactors code entry point setting logic for portable entry points
src/coreclr/vm/jitinterface.cpp	Optimizes helper function entry point creation and caching
src/coreclr/vm/gchelpers.cpp	Updates array allocation to use new SetNumComponents method
src/coreclr/vm/gcheaputilities.h	Refactors allocation context methods for better encapsulation
src/coreclr/vm/finalizerthread.h	Moves RaiseShutdownEvents implementation to source file
src/coreclr/vm/finalizerthread.cpp	Implements RaiseShutdownEvents with WASM-specific handling
src/coreclr/vm/ecall.h	Adds optional output parameter for managed implementation detection
src/coreclr/vm/ecall.cpp	Enhances FCall implementation detection and managed constructor handling
src/coreclr/vm/callstubgenerator.cpp	Fixes variable shadowing in call stub generation
src/coreclr/runtime/portable/AllocFast.cpp	Implements fast array and string allocation with allocation context management
src/coreclr/nativeaot/Runtime/portable.cpp	Updates NativeAOT allocation helpers to use consistent method names
src/coreclr/nativeaot/Runtime/ObjectLayout.h	Standardizes method naming for array initialization
src/coreclr/nativeaot/Runtime/ObjectLayout.cpp	Updates method implementation to match new naming convention
src/coreclr/nativeaot/Runtime/GCHelpers.cpp	Updates allocation helper to use SetMethodTable naming

[jkotas]

Thank you!

[pavelsavara]

I tested it and it works 🎉

[jkotas]

Revert "Update src/coreclr/vm/jitinterface.cpp"

This hit a buggy path discussed in #119355 (comment) . I have reapplied the feedback with additional fix.

[radekdoulik]

LGTM, I will address the remaining feedback on caching cookie in another PR

[AaronRobinsonMSFT]

Revert "Update src/coreclr/vm/jitinterface.cpp"

This hit a buggy path discussed in #119355 (comment) . I have reapplied the feedback with additional fix.

FYI @kotlarmilos