Update MIPS math-tests.h for GCC 4.9 using soft-fp.
GCC trunk now uses soft-fp for MIPS64 long double, so supporting
integration with hardware exceptions and rounding modes. This patch
updates MIPS math-tests.h accordingly not to disable exception and
rounding mode tests in this case.
Tested mips64 and ulps updated to reflect the newly run tests.
* sysdeps/mips/math-tests.h: Include <features.h>.
[!__mips_soft_float && _MIPS_SIM != _ABIO32 && __GNUC_PREREQ (4, 9)]
(ROUNDING_TESTS_long_double): Do not define.
[!__mips_soft_float && _MIPS_SIM != _ABIO32 && __GNUC_PREREQ (4, 9)]
(EXCEPTION_TESTS_long_double): Likewise.
* sysdeps/mips/mips64/libm-test-ulps: Update.