Allow user code to be compiled with "-mhard-float" for armeabi-v7a
(which implies -mfloat-abi=hard), and either link with
1. Android native APIs which use softfp, or
2. A customized libm_hard.a which is compiled with -mhard-float. Need
-D_NDK_MATH_NO_SOFTFP=1
See tests/device/hard-float/jni/Android.mk for details and restriction
on Clang
Change-Id: I773a842c73368e08b9a6cda0441e95a96fa303b2
1. Add sincos, sincosf, and sincosl to API >= 9 (for ARM only,
because X86 and MIPS have it already)
2. Add nan, nanf, nanl, and tgammaf to API >= 13 (11 actually,
but we don't want to add another API which is not released)
3. Add log2, log2f, log2l, logbl, nexttoward, and nexttowardl to
API >= 18
See b.android.com/38423
Change-Id: I0a756aeeddafc3862f3c0ae38218cb3301608231
