1. Only for fixed point on x86 platform (32bit and 64bit, uses SIMD
intrinsics up to SSE4.2)
2. Use "configure --enable-fixed-point --enable-intrinsics" to enable
optimization, default is disabled.
3. Official test cases are verified and passed.
Signed-off-by: Timothy B. Terriberry <tterribe@xiph.org>
Newer versions of MSVC are unhappy with the strategy of the build
environment redefining "inline" (even though they don't support the
actual keyword). Instead we define OPUS_INLINE to the right thing
in opus_defines.h.
This is the same approach we use for restrict.
