[clang][bytecode][x86] Merge interp__builtin_ia32_pmul/interp__builtin_ia32_pmadd implementations (#162504)
The interp__builtin_ia32_pmadd implementation can be correctly used for
PMULDQ/PMULUDQ evaluation as well as we're ignoring the "hi" integers in
each pair
I've replaced the PMULDQ/PMULUDQ evaluation with callbacks and renamed
interp__builtin_ia32_pmadd to interp__builtin_ia32_pmul for consistency