objsz: Don't call replace_uses_by on SSA_NAME_OCCURS_IN_ABNORMAL_PHI [PR94423]

objsz: Don't call replace_uses_by on SSA_NAME_OCCURS_IN_ABNORMAL_PHI [PR94423]

The following testcase ICEs because the objsz pass calls replace_uses_by
on SSA_NAME_OCCURS_IN_ABNORMAL_PHI SSA_NAME.  The following patch instead
of that calls replace_call_with_value, which will turn it into
  xyz_123(ab) = 234;

2020-04-01  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/94423
	* tree-object-size.c (pass_object_sizes::execute): Don't call
	replace_uses_by for SSA_NAME_OCCURS_IN_ABNORMAL_PHI lhs, instead
	call replace_call_with_value.

	* gcc.dg/ubsan/pr94423.c: New test.