Regressions on native/master at commit r14-8757 vs commit r14-8751 on Linux/x86_64

[H. J. Lu]

Regressions on native/master at commit r14-8757 vs commit r14-8751 on Linux/x86_64
New failures:
FAIL: 30_threads/future/members/poll.cc  -std=gnu++17 execution test
FAIL: gcc.dg/lto/save-temps c_lto_save-temps_0.o-c_lto_save-temps_0.o link,  -O -flto -save-temps
FAIL: gcc.dg/torture/convert-dfp-2.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)
FAIL: gcc.dg/torture/convert-dfp.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)

New passes: