[interp] Verify stack depth for return opcodes

[kg]

Fixes JIT\regression\jitblue\GitHub_25027

[Copilot]

Pull Request Overview

This PR adds stack depth verification for return opcodes in the CoreCLR interpreter to ensure the evaluation stack has exactly the expected number of items when returning from a method. This addresses a regression test failure in GitHub_25027.

Key changes:

• Introduces a new CheckStackExact method that validates the stack has precisely the expected depth
• Replaces existing CHECK_STACK calls with CheckStackExact for return operations to catch both stack underflow and overflow conditions

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/coreclr/interpreter/compiler.h	Adds declaration for new CheckStackExact method
src/coreclr/interpreter/compiler.cpp	Implements CheckStackExact and applies it to return opcodes for precise stack validation

Comments suppressed due to low confidence (2)

src/coreclr/interpreter/compiler.cpp:3928

• The removed CHECK_STACK(1) call should be documented or explained in the commit message why it was replaced, as this represents a behavior change from checking minimum stack depth to exact stack depth.

                {

src/coreclr/interpreter/compiler.cpp:3947

• The removed CHECK_STACK(1) call should be documented or explained in the commit message why it was replaced, as this represents a behavior change from checking minimum stack depth to exact stack depth.

                CHECK_STACK(1);

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