Regressions on trunk at revision 258348 vs revision 258336

[H.J. Lu Intel64 -fpic -mcmodel=medium -mcmodel=large]

New failures:

New passes:
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++11  (test for warnings, line )
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++11  (test for warnings, line )
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++11  (test for warnings, line 108)
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++11  (test for warnings, line 108)
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++14  (test for warnings, line )
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++14  (test for warnings, line )
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++14  (test for warnings, line 108)
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++14  (test for warnings, line 108)
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++98  (test for warnings, line )
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++98  (test for warnings, line )
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++98  (test for warnings, line 108)
FAIL: g++.dg/warn/Wstringop-truncation-1.C  -std=gnu++98  (test for warnings, line 108)