Skip interpreter selection when dynamic compilation is unavailable

[jkoritzinsky]

When `FEATURE_DYNAMIC_CODE_COMPILED` is absent, `CILInterp::compileMethod` must interpret every method. Previously it still ran interpreter-versus-JIT selection before deciding to always interpret anyway.

Compile out selection and module tracking when dynamic compilation is unavailable. I chose to keep a cheap unsigned InterpMode range check that preserves rejection of values outside 0-3 with the same exception and failure stage, but we can remove this also to further reduce code size.

Conditional interpreter selection remains unchanged.

Codegen evidence

Independently resolved, matching browser Release WASM binaries and symbol maps show the three selection-only indirect call sites are gone. The compileMethod body decreases from 84,606 to 84,510 bytes, with 194 to 191 indirect call sites. Later compilation metadata queries remain.

Note

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