Regressions on trunk at revision 265517 vs revision 265498

[H.J. Lu (ia32 -fpic)]

New failures:
FAIL: gcc.dg/pr78973-2.c ilp32 (test for warnings, line 16)
FAIL: g++.dg/ubsan/vla-1.C   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  execution test
FAIL: g++.dg/ubsan/vla-1.C   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  execution test

New passes: