[CSSPGO] Avoid deleting probe instruction in FoldValueComparisonIntoPredecessors
This change tries to fix a place missing moveAndDanglePseudoProbes . In FoldValueComparisonIntoPredecessors, it folds the BB into predecessors and then marked the BB unreachable. However, the original logic from the BB is still alive, deleting the probe will mislead the SampleLoader mark it as zero count sample.
Reviewed By: hoy, wenlei
Differential Revision: https://reviews.llvm.org/D102721