replace inline assembly WebRtcNsx_AnalysisUpdate by intrinsics.

The modification only uses the unique part of the analysis_update
 function. Pass byte to byte conformance test on both ARMv7 and AArch64,
 and the single function performance is similar with original assembly
 version on different platforms. If not specified, the code is compiled
 by GCC 4.6. The result is the "X version / C version" ratio, and the
 less is better.

| run 100k times             | cortex-a7 | cortex-a9 | cortex-a15 |
| use C as the base on each  |  (1.2Ghz) |  (1.0Ghz) |   (1.7Ghz) |
| CPU target                 |           |           |            |
|----------------------------+-----------+-----------+------------|
| Neon asm                   |    15.61% |    20.15% |     14.89% |
| Neon inline asm (LLVM 3.4) |    25.98% |    33.96% |     18.18% |
| Neon intrinsics (GCC 4.6)  |    22.06% |    27.01% |     19.24% |
| Neon intrinsics (GCC 4.8)  |    17.28% |    18.23% |     18.55% |
| Neon intrinsics (LLVM 3.4) |    21.02% |    19.98% |     16.76% |

BUG=
R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/28849004

Patch from Zhongwei Yao <zhongwei.yao@arm.com>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7596 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed