[X86] Add support for using Sched/Codesize information to `X86FixupInstTuning` Pass.

Use this to handle new transform: `{v}unpck{l|h}pd` -> `{v}shufps`. We
need the sched information here as `{v}shufps` is 1 more byte of code
size, so we only want to make this transformation if `{v}shufps` is
actually faster.

Differential Revision: https://reviews.llvm.org/D144570