…n MIPS
Modify:
Add a global variable 'CurForbiddenSlotAttr' to save current
instruction's forbidden slot and whether set reorder. This is the
judgment condition for whether to add nop. We would add a couple of
'.set noreorder' and '.set reorder' to wrap the current instruction and
the next instruction.
Then we can get previous instruction`s forbidden slot attribute and
whether set reorder by 'CurForbiddenSlotAttr'.
If previous instruction has forbidden slot and .set reorder is active
and current instruction is CTI. Then emit a NOP after it.
Fix https://github.com/llvm/llvm-project/issues/61045.
Because https://reviews.llvm.org/D158589 was 'Needs Review' state, not
ending, so we commit pull request again.