[ARM] Don't form "ands" when it isn't scheduled correctly.
In r322972/r323136, the iteration here was changed to catch cases at
the beginning of a basic block... but we accidentally deleted an
important safety check. Restore that check to the way it was.
Fixes https://bugs.llvm.org/show_bug.cgi?id=41116
Differential Revision: https://reviews.llvm.org/D59680
This should fix "Assertion failed: (LiveCPSR && "CPSR liveness tracking
is wrong!"), function UpdateCPSRUse" errors when building the devel/xwpe
port for armv7.
PR: 236062, 236568
MFC after: 1 month
X-MFC-With: r344779