Regressions on trunk at revision 261908 vs revision 261888

[H.J. Lu x32]

New failures:

New passes:
FAIL: 21_strings/basic_string/modifiers/64422.cc (test for excess errors)
FAIL: 21_strings/basic_string/modifiers/insert/char/1.cc (test for excess errors)
FAIL: 21_strings/basic_string/modifiers/insert/wchar_t/1.cc (test for excess errors)
FAIL: g++.dg/torture/pr60750.C   -O0  (test for excess errors)
FAIL: g++.dg/torture/pr60750.C   -Os  (test for excess errors)
FAIL: libstdc++-abi/abi_check