[wasm][R2R] Runtime_101046 returns incorrect sign extension #133506

Description

JIT/Regression/JitBlue/Runtime_101046 returns 101 in browser-wasm CoreCLR ReadyToRun execution. The test validates sign extension of a native small-integer return.

Reproduction Steps

Run the default runtime pipeline for #133463 at commit 452dea3aba16d97244508b8a0fef4643de8dd26e (Azure DevOps build 1589007, test run 43860850).

Expected behavior

Runtime101046Native.ReturnExtendedShort((short)p) returns -123, and the test exits 100.

Actual behavior

The test exits 101 only in the wasm ReadyToRun scenario.

Regression?

Unknown; exposed by the restored browser-wasm R2R lane.

Known Workarounds

Mark only this out-of-process test project R2R-incompatible for wasm CoreCLR. Normal wasm execution and non-wasm coverage remain enabled.

Configuration

• CoreCLR browser-wasm
• Checked runtime
• ReadyToRun / crossgen2

Other information

This is distinct from #131811, which records the test-specific native asset as enabled and passing outside this R2R-only ABI failure. Umbrella tracking: #133305.