Hi,
  As described in the bug, tree-if-conv is calling update_stmt on an
old stmt which might have been removed from the IR already
(transforming of an assignment to a call in this case).  This fixes
the problem by calling update_stmt on the new statement that fold_stmt
might have created.

OK?  Bootstrapped and tested on aarch64-linux-gnu with no regressions.

Thanks,
Andrew Pinski
ChangeLog:
* tree-if-conv.c (predicate_scalar_phi): Update new_stmt if fold_stmt
returned true.

testsuite/ChangeLog:
* gcc.dg/torture/pr81245.c: New testcase.