Previously there was a limit of two cpuflags.

Reduce the number of vector registers used from 7 to 5.
Eliminate some moves in the AVX implementation.
Avoid bypass delays for transitioning between int and float domains.

Also drop the MMX version instead of doing a bunch of ifdeffery to support it after this change.

Deblock chroma/luma are based on libav's h264 aarch64 NEON deblocking
filter which was ported by me from the existing ARM NEON asm. No
additional persons to ask for a relicense.

Ported from the ARM NEON asm.

Ported from the ARM NEON asm.

Ported from the ARM NEON asm.

Ported from the ARM NEON asm.

Ported from the ARM NEON asm.

9-19% faster on a cortex-a9.

mc_weight_w4_*neon is also used for width 2 which does not guarantee
4-byte aligned destination. Fixes crashes caused by random memory
corruption.

The memory acts as compiler barrier preventing aggressive reordering
of read_time calls. gcc 4.8 reorders some of initial read_time calls
after the second when targeting arm.

The integrated assembler in llvm trunk (to be released as 3.5) is
otherwise capable enough to assemble the arm asm correctly.

The gas manual states "Repeat the sequence of lines between the .rept
directive and the next .endr directive ...". GNU as seems to support
instructions on the same line as .rept anyway but the integrated
assembler in llvm trunk (to be released 3.5 in August 2014) does not.

Help remind people to call x264_param_default in case they didn't read the
documentation.

The first MSVS compiler C99 compliant enough to build x264.
Use `CC=cl ./configure` to compile with it.