[Sema][X86] Update immediate check for gather/scatter prefetch instructions to...

[Sema][X86] Update immediate check for gather/scatter prefetch instructions to match the _MM_HINT_T0/T1 constant definitions

Our _MM_HINT_T0/T1 constant values are 3/2 which matches gcc, but not icc or Intel documentation. Interestingly gcc had this same bug on their implementation of the gather/scatter builtins at one point too.

Fixes PR32411.

llvm-svn: 299233