[clr-interp] Enable rejit in the interpreter

[davidwrighton]

• Rely on resetting the interpreter code pointer to trigger the existing rejit/prestub logic to fill in any gaps we have.

This fixes the rejit test

[dotnet-policy-service]

Tagging subscribers to this area: @BrzVlad, @janvorli, @kg
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

This pull request enables ReJIT support in the interpreter by adding calls to clear the interpreter code pointer at strategic points in the code versioning and entry point management flow. The changes ensure that when code versions are updated or reset, the interpreter state is properly cleared, allowing the existing rejit/prestub logic to rebuild the interpreter state as needed.

• Adds ClearInterpreterCodePointer() calls in ResetCodeEntryPoint() and ResetCodeEntryPointForEnC() to clear interpreter state during entry point resets
• Adds ClearInterpreterCodePointer() in PublishNativeCodeVersion() when setting new native code versions to ensure interpreter state is synchronized with code versioning

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/coreclr/vm/method.cpp	Adds interpreter code pointer clearing in two entry point reset methods to support rejit scenarios
src/coreclr/vm/codeversion.cpp	Clears interpreter code pointer when publishing new native code versions to ensure proper rejit behavior

[Copilot]

Trailing whitespace detected at the end of this line. According to the repository's code formatting conventions, there should be no trailing whitespace.

Suggested change

	#endif
	#endif

[Copilot]

The indentation of the preprocessor directives is inconsistent with the surrounding code. The '#ifdef' and '#endif' directives should be aligned at column 0 (no indentation), following the standard C/C++ convention and the pattern used elsewhere in this file.

Suggested change

	#ifdef FEATURE_INTERPRETER
	// When we hit the Precode that should fixup any issues with an unset interpreter code pointer. This is notably most important in ReJIT scenarios
	pMethod->ClearInterpreterCodePointer();
	#endif
	#ifdef FEATURE_TIERED_COMPILATION
	#ifdef FEATURE_INTERPRETER
	// When we hit the Precode that should fixup any issues with an unset interpreter code pointer. This is notably most important in ReJIT scenarios
	pMethod->ClearInterpreterCodePointer();
	#endif
	#ifdef FEATURE_TIERED_COMPILATION

[BrzVlad]

Is this resetting of the code pointer for a method the same mechanism that is used also for EnC functionality when debugging. I suspect precodes might also need flushing, but this might already be integrated with the rest of the runtime ?