Regressions on trunk at revision 187007 vs revision 186978

[H.J. Lu ia32 Core 2/i7]

New failures:

New passes:
FAIL: gcc.dg/pr52283.c (test for excess errors)
FAIL: gcc.target/i386/bmi2-mulx32-1a.c scan-assembler-times bmi2_umulsidi3_1 1
FAIL: gcc.target/i386/bmi2-mulx32-2a.c scan-assembler-times mulx[ \\t]+[^\n]* 1