Fix -mhard-float for calling __builtin_* math functions

Annotate __builtin math functions with __NDK_FPABI_MATH__ too.
1. __attribute__((pcs("aapcs"))) has no effect on codegen when __buitlin
   function is emitted inlined.
2. When __builtin call into regular function in Android's libm, it has
   proper attribute which observes soft float-abi

Change-Id: I11e8b74fc22f3072b9ce849193e4a56e98c92d64
4 files changed