[InstrRef] Preserve debug instr num in aarch64-cond-br-tuning. (#132081)
The aarch64-cond-br-tuning pass transforms a CBZX instruction into a
conditional branch (B.cond). One of the by products of the
transformation is that the source instruction of the CBZX, which is an
ANDXri instruction, gets transformed into a ANDSXri instruction, however
this transformation doesn't preserve it's debug instruction number.
This patch fixes that issue.