[X86] Broadwell load latencies don't match similar targets

[RKSimon]

Bugzilla Link	39188
Version	trunk
OS	Windows NT
Blocks	#31672
CC	@legrosbuffle,@topperc

Extended Description

The Broadwell scheduler model indicates that it has faster load latencies than both the previous Haswell and the successor Skylake targets.

Its more likely the Broadwell are incorrect.