Bionic/libm: fast neon pow() for small x,y

Add a fast neon version of pow() suitable for relatively small
positive x and y (between 0 and 4).  Run the standard
implementation in all other cases.  Gives approximately 60%
performance improvement to AnTuTu FPU score.

Change-Id: I9234d37eaa6a815d1e619375f5b049c4ec88f557

Conflicts:
	libm/Android.mk
	libm/arm/e_pow.S
	libm/src/e_pow.c
msm7627a: Enable neon optimized memove and pow functions.

Define SPARROW_NEON_OPTIMIZATION flag so that neon optimized
memove and pow functions are used. Also add Corresponding
definitions in make files.

Change-Id: I12089fc7002e3ec294e63632bd84e395fbd24936
Bionic/libm: Prefer branches and VFP ABI

For internal functions set gcc attribute "aapcs-vfp" for ARM
and use -fno-if-conversion to prefer branches over predicated
instructions (improves performance on architectures with good
branch prediction).

Change-Id: I365e9508bd3babb0bb06fc5de127c1ae17445bcc
Bionic/libm: add assembly versions of sin/cos

Add assembly versions of sin/cos with integrated remainder pi/2
calculation.  Directly extracted from binary libm.so compiled with
__ieee754_rem_pio2 calls inlined.

Change-Id: I9a999c01cea92aace9df7be9ad8f90f150040375

Conflicts:
	libm/arm/s_cos.S
	libm/arm/s_sin.S
Bionic/libm: Remove extra vmov from sin/cos

Move integer representations of x bits on the integer side rather
than moving them to and from the FP registers.

Change-Id: I1d0800730d7553a47c462ee2a0cc044ffe62eb20
Bionic/libm: Pow optimizations and bug fixes

Use VFP calling convention for pow_neon handoff function by default.
Fix register usage collision between two different polynomial
coefficients in pow_neon.  Remove conditional execution in pow_neon
and replace with branching.

Change-Id: I254617940b2787297aff2ab97dbf45c11e6a2b08

Conflicts:
	libm/arm/e_pow.S
	libm/src/e_pow.c
msm7627a: libm: Prefer branches and VFP ABI
This is merely applying the following for sparrow: https://bitbucket.org/codefirex/bionic/commits/586ec6f129def5b0407cbdaeebe4ac59c194c255
Bionic/libm: Add precision-correct de-serialize sin/cos for msm7627a
enable the following for msm7627a: https://bitbucket.org/codefirex/bionic/commits/1c65bf43cf2d5ce822ae7941aca9d350ca6c22fc
libc: add optimized linaro bzero routine