Fix spurious "inexact" exceptions from x86 pow with NaN argument (bug 16167).
Make libm-test.inc check for "inexact" exceptions for NaN argument.
Replace libm-test.inc TEST_INLINE conditionals with NO_TEST_INLINE flag.
Add libm-test support for ignored return value, add more lrint / llrint / lround / llround tests.
Test signs of NaNs in libm-test.inc where appropriate.