[X86] Split ReadAfterLd into ReadAfterLd/ReadAfterFLd/ReadAfterVecLd

[RKSimon]

Bugzilla Link	36957
Resolution	FIXED
Resolved on	Oct 06, 2018 03:24
Version	trunk
OS	Windows NT
Blocks	#31672
CC	@adibiagio,@legrosbuffle,@topperc
Fixed by commit(s)	343868

Extended Description

Similar to what was done for WriteLoad, we need to split ReadAfterLd to more correctly allow for the different load latencies on gpr, float and vector-int instructions.

[RKSimon]

Candidate Patch: https://reviews.llvm.org/D52886

[RKSimon]

https://reviews.llvm.org/rL343868