[mono] Re-enable passing Vector128 arguments in SIMD registers

[lambdageek]

Due to mixing LLVM and non-LLVM code (see #73454) we disabled the work done for #68991 to pass arguments in SIMD registers. Once the JIT (and interp?) can also use the SIMD registers, we should re-enable that code.

#74582

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Issue Details

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Due to mixing LLVM and non-LLVM code (see #73454) we disabled the work done for #68991 to pass arguments in SIMD registers. Once the JIT (and interp?) can also use the SIMD registers, we should re-enable that code.

#74582

Author:	lambdageek
Assignees:	-
Labels:	area-CodeGen-coreclr, untriaged
Milestone:	-

[lambdageek]

/cc @vargaz @fanyang-mono @SamMonoRT

[SamMonoRT]

Assigning to @fanyang-mono for tracking and consolidating related issues for 8.0.0