Upstream has implemented lgammal/lgammal_r for ld128, and fixed the
sign problem we reported with all the lgamma*_r functions and -0.
Bug: 17471883
Change-Id: Ibb175d9cab67efae75f1010796fd44c9ba6ce4fc
* reworked amd64/_fpmath.h and arm64/_fpmath.h to support 128-bit long
doubles.
* improved tests to cover long double cases
* made modfl an alias for LP32
Tests pass on x86, x86_64, arm, arm64 and mips.
Bug: 12921273
Change-Id: Ibe39acde57972447a8950fa45b1e702acc68ebeb