tree-inline: Fix up __builtin_va_arg_pack handling [PR100898]
The following testcase ICEs, because gimple_call_arg_ptr (..., 0)
asserts that there is at least one argument, while we were using
it even if we didn't copy anything just to get a pointer from/to which
the zero arguments should be copied.
Fixed by guarding the memcpy calls. Also, the code was calling
gimple_call_num_args too many times - 5 times instead of 2, so the patch
adds two temporaries for those.
2021-06-07 Jakub Jelinek <jakub@redhat.com>
PR middle-end/100898
* tree-inline.c (copy_bb): Only use gimple_call_arg_ptr if memcpy
should copy any arguments. Don't call gimple_call_num_args
on id->call_stmt or call_stmt more than once.
* g++.dg/ext/va-arg-pack-3.C: New test.