[wasm] Add Vector128 and PackedSimd support to the jiterpreter; add PackedSimd to the interpreter (#82773)
* Add PackedSIMD support to the interpreter (off by default)
* Add SIMD support to the jiterpreter
* Add runtime options governing interpreter vector128 and packedsimd support
* Add some R4 vector128 operations to the interpreter
* Fix jiterpreter MINT_POPCNT_I8 implementation
* Enable compiling the runtime with wasm simd support so that intrinsics can be used
* Add browser-bench measurements for packing vector128