libc: krait: Use performance version of bcopy and memmove

Ported from CM10.2.

bionic-benchmarks on mako:
before:
                     iterations      ns/op
BM_string_memmove/8    50000000         32   243.54 MiB/s
BM_string_memmove/64   20000000        143   446.41 MiB/s
BM_string_memmove/512    2000000        885   578.14 MiB/s
BM_string_memmove/1K    1000000       1733   590.55 MiB/s
BM_string_memmove/8K     200000      13618   601.54 MiB/s
BM_string_memmove/16K     100000      27276   600.66 MiB/s
BM_string_memmove/32K      50000      59115   554.30 MiB/s
BM_string_memmove/64K      10000     118162   554.63 MiB/s

after:
                     iterations      ns/op
BM_string_memmove/8    50000000         20   381.94 MiB/s
BM_string_memmove/64  100000000         17  3636.07 MiB/s
BM_string_memmove/512   50000000         50 10116.80 MiB/s
BM_string_memmove/1K   20000000         98 10429.23 MiB/s
BM_string_memmove/8K    2000000        876  9346.43 MiB/s
BM_string_memmove/16K    1000000       1836  8923.09 MiB/s
BM_string_memmove/32K     500000       4392  7459.79 MiB/s
BM_string_memmove/64K     200000       8562  7653.85 MiB/s

Change-Id: Id64913a71857d9cfdf6bd1bbe2c66cfc49d72748
libc: krait: Implement optimized versions of memmove and bcopy

Restore a jellybean optimization for memmove and bcopy on krait.
Code has been refactored to thumb2 for consistency with the rest of
bionic libc, as well as performance and correctness.

Change-Id: I8f2f77dce4534fbce1bdf0188ab353bf34ab8637
libc: Enable high-performance memmove and bcopy for cortex-a15

Change-Id: Id8e4e595021dd13bf4ab5620f5fb0b0d80333616
Revert "libc: Fix Scorpion-optimized calls"

This reverts commit 1cf47bd7b4a57879e3cdaefeb3d932c6679ffba8.
libc: Unbreak build for scorpion

Use cortex-a15 memcpy and krait memset routines

Change-Id: I02cb178b33b01fc91e903f1f7b620640fd0f3310