This CL unconditionally removes the existance of __builtin_isinf and
__builtin_isnan from math.h for clang, because (unlike other math functions)
clang doesn't like those to be declared.
See LLVM bugzilla entry: http://llvm.org/bugs/show_bug.cgi?id=20958
The reason for decorating all math functions with __attribute__((pcs("aapcs")))
is to offer developers the ability to compile their code with hardfp and still
link Android's libm.so which follows softfp calling convention.
Before issue 20958 is fixed, those who want clang to compile their code with
hardfp in NDK has to go all the way hard, ie.
1) LOCAL_CFLAGS += -mhard-float -D_NDK_MATH_NO_SOFTFP=1
Note that _NDK_MATH_NO_SOFTFP=1 remove __attribute__((pcs("aapcs"))) for all math functions
2) LOCAL_LDLIBS += -lm_hard # link libm_hard.a recompiled with -mhard-float instead of bionic libm.so
Change-Id: Ie2f95e73e58e1574e8cadbcab92a5209d94448e1
3598d53b42