Hello.

I'm going to do merge from upstream.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests. I've also tested
on ppc64le-linux-gnu and verified the ABI.

The only real change is a small change in
gcc/testsuite/c-c++-common/asan/alloca_loop_unpoisoning.c
where we need --param=asan-use-after-return=0.

I'm going to push the patches.

Thanks,
Martin