[X86] Cmov converter pass sinks volatile loads

[topperc]

Bugzilla Link	42922
Version	trunk
OS	Windows NT
CC	@topperc,@RKSimon,@rotateright,@TNorthover

Extended Description

When the cmov converter pass expands a volatile load that has been folded with a cmov, it places the load only on the false path of the created control flow. But a volatile load should be executed unconditionally. The original cmov instruction would have always executed the load.