Bionic: Add AOSP master cortex optimizations

libc/arch-arm/bionic/memcpy.a9.S: memcpy from cortex-strings.

This memcpy code uses NEON/VFP to achieve very good performance
on ARMv7-A processors. It is specifically tuned for A15 but should
provide good performance on A9 also. It is equivalent to the code
in cortex-strings rev 116.

This patch is a follow up the existing gerrit change:

I7f6f77995f3ca903ad9c66d14261441667a2a935

But this version includes a tweak for performance on misaligned
buffers.

Change-Id: I285abac0068f8ae29a1cbf7862ea8590aadaf0a7
Signed-off-by: Will Newton <will.newton@linaro.org>

libc/arch-arm/bionic/memcpy.a9.S: memcpy from cortex-strings.

This memcpy code uses NEON/VFP to achieve very good performance
on ARMv7-A processors. It is specifically tuned for A15 but should
provide good performance on A9 also. It is equivalent to the code
in cortex-strings rev 116.

This patch is a follow up the existing gerrit change:

I7f6f77995f3ca903ad9c66d14261441667a2a935

This version includes a tweak for performance on misaligned
buffers and splits the header comment into license and
documentation sections.

Change-Id: Ibd2e23c8d8e01357ba0247be1d05192de3ceba69
Signed-off-by: Will Newton <will.newton@linaro.org>

Add new optimized strlen for arm.

This optimized version is primarily targeted at cortex-a15.

Tested on all nexus devices using the system/extras/libc_test strlen test.
Tested alignments from 1 to 32 that are powers of 2.
Tested that strlen does not cross page boundaries at all alignments.

Speed improvements listed below:

cortex-a15
- Sizes >= 32 bytes, ~75% improvement.
- Sizes >= 1024 bytes, ~250% improvement.

cortex-a9
- Sizes >= 32 bytes, ~75% improvement.
- Sizes >= 1024 bytes, ~85% improvement.

krait
- Sizes >= 32 bytes, ~95% improvement.
- Sizes >= 1024 bytes, ~160% improvement.

Merge from internal master.

(cherry-picked from 2fc071797743b88a9a47427d46baed7c7b24f4d2)

Change-Id: I1ceceb4e745fd68e9d946f96d1d42e0cdaff6ccf

Conflicts:
	libc/arch-arm/generic/generic.mk
	libc/arch-arm/krait/krait.mk

libgcc_compat: Introduce __aeabi_lasr for cortex-a9 and higher

This is needed when passing -mcpu=cortex-a9 or higher on a modern
toolchain for prebuilt library compatibility
libc: Optimize strcat/strcpy, small tweaks to strlen

Create one version of strcat/strcpy/strlen for cortex-a15/krait/scorpion and another
version for cortex-a9.

Tested with the libc_test strcat/strcpy/strlen tests.
Including new tests that verify that the src for strcat/strcpy do not
overread across page boundaries.

NOTE: The handling of unaligned strcpy (same code in strcat) could probably
be optimized further such that the src is read 64 bits at a time instead of
the partial reads occurring now.

strlen improves slightly since it was recently optimized.

Performance improvements for strcpy and strcat (using an empty dest string):

cortex-a9
- Small copies vary from about 5% to 20% as the size gets above 10 bytes.
- Copies >= 1024, about a 60% improvement.
- Unaligned copies, from about 40% improvement.

cortex-a15
- Most small copies exhibit a 100% improvement, a few copies only
  improve by 20%.
- Copies >= 1024, about 150% improvement.
- Unaligned copies, about 100% improvement.

krait
- Most small copies vary widely, but on average 20% improvement, then
  the performance gets better, hitting about a 100% improvement when
  copies 64 bytes of data.
- Copies >= 1024, about 100% improvement.
- When coping MBs of data, about 50% improvement.
- Unaligned copies, about 90% improvement.

As strcat destination strings get larger in size:

cortex-a9
- about 40% improvement for small dst strings (>= 32).
- about 250% improvement for dst strings >= 1024.

cortex-a15
- about 200% improvement for small dst strings (>=32).
- about 250% improvement for dst strings >= 1024.

krait
- about 25% improvement for small dst strings (>=32).
- about 100% improvement for dst strings >=1024.

Merge from internal master.

(cherry-picked from d119b7b6f48fe507088cfb98bcafa99b320fd884)

Change-Id: I296463b251ef9fab004ee4dded2793feca5b547a

Conflicts:
	libc/Android.mk
	libc/arch-arm/generic/generic.mk
	libc/arch-arm/krait/krait.mk

Fix strcpy.c that should have been strcpy.S

Merge from internal master.

(cherry-picked from 1ce665416307628f4bcaced86faa64bdf9c489c3)

Conflicts:
	libc/arch-arm/generic/generic.mk

Change-Id: I376b831df42248baadde7202a30a68112f752ff7
libc: Add NEON optimized memmove

ported from cm10.1

bionic-benchmarks on cortex-a9
generic:
BM_string_memmove/8    50000000         67   119.35 MiB/s
BM_string_memmove/64   10000000        175   364.59 MiB/s
BM_string_memmove/512   1000000       1078   474.86 MiB/s
BM_string_memmove/1K    1000000       2072   494.20 MiB/s
BM_string_memmove/8K     100000      16400   499.50 MiB/s
BM_string_memmove/16K     50000      32293   507.35 MiB/s
BM_string_memmove/32K     50000      66585   492.12 MiB/s
BM_string_memmove/64K     10000     160435   408.49 MiB/s

NEON-optimized:
BM_string_memmove/8   100000000         25   319.06 MiB/s
BM_string_memmove/64   50000000         43  1472.60 MiB/s
BM_string_memmove/512  10000000        247  2069.74 MiB/s
BM_string_memmove/1K    5000000        463  2210.08 MiB/s
BM_string_memmove/8K     500000       3465  2363.69 MiB/s
BM_string_memmove/16K    500000       6894  2376.30 MiB/s
BM_string_memmove/32K    100000      15490  2115.38 MiB/s
BM_string_memmove/64K     50000      42097  1556.75 MiB/s

Change-Id: I89253a01fb811438089e16320ac265177a2ca152