libc: import ARM strcmp from newlib

* Current version is also based on newlib, but an older revision

* The Krait and A9 specific changes no longer seem relevant, so
  let's use A15 directly.

Tested on OnePlus 3 (MSM8996):

Before (Krait strcmp):
                                       iterations      ns/op
BM_string_strcmp/8                          1000k         24    0.322 GiB/s
BM_string_strcmp/64                           20M        123    0.519 GiB/s
BM_string_strcmp/512                           2M        920    0.556 GiB/s
BM_string_strcmp/1024                       1000k       1818    0.563 GiB/s
BM_string_strcmp/8Ki                         200k      14405    0.569 GiB/s
BM_string_strcmp/16Ki                        100k      28762    0.570 GiB/s
BM_string_strcmp/32Ki                         50k      57526    0.570 GiB/s
BM_string_strcmp/64Ki                         10k     114959    0.570 GiB/s

After:
                                       iterations      ns/op
BM_string_strcmp/8                          1000k         28    0.284 GiB/s
BM_string_strcmp/64                           20M        107    0.596 GiB/s
BM_string_strcmp/512                           2M        800    0.639 GiB/s
BM_string_strcmp/1024                       1000k       1579    0.649 GiB/s
BM_string_strcmp/8Ki                         200k      12469    0.657 GiB/s
BM_string_strcmp/16Ki                        100k      24931    0.657 GiB/s
BM_string_strcmp/32Ki                         50k      49843    0.657 GiB/s
BM_string_strcmp/64Ki                         20k      99635    0.658 GiB/s

Test: bionic-benchmarks BM_string_memcmp
Change-Id: Icb3bfb0a381bcc1e10885ca5e9547842c3f620d7
diff --git a/libc/NOTICE b/libc/NOTICE
index 298901f..ef31733 100644
--- a/libc/NOTICE
+++ b/libc/NOTICE
@@ -5330,6 +5330,34 @@
 
 -------------------------------------------------------------------
 
+Copyright (c) 2012-2014 ARM Ltd
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+3. The name of the company may not be used to endorse or promote
+   products derived from this software without specific prior written
+   permission.
+
+THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED
+WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
 Copyright (c) 2013
      MIPS Technologies, Inc., California.