[EarlyCSE] Fix dead store elimination for unwinding readnone calls (#145287)

EarlyCSE already resets LastStore when it hits an potentially unwinding
instruction, as the memory state may be observed by the caller after the
unwind.

There also was a test specifically making sure that this works even for
unwinding readnone calls -- however, the call in that test did not
participate in EarlyCSE in the first place, because it returns void
(relaxing that is how I got here), so it was not actually testing the
right thing.

Move the check for unwinding instructions earlier, so it also handles
the readnone case.

0 files changed, 0 insertions, 0 deletions