Don't set it when building with 'nasm'

Change-Id: I01c211090f6870e0d34011f867471249a5f54bb0

Other implementations of x86inc.asm have more comprehensive nasm
workarounds. This is the only thing that was changed for the previous
import to libvpx. See if we can still get away with it.

Change-Id: I3ef6fe9a4816461c89431a82b7e4a08b4b948d39

Make sure all variants get correct visibility and SECTION notes.

libvpx only pass elf32 and elf64 to the assembler, never just elf.

Change-Id: I7c36c115bf52436c9afe61985c859a2081948271

Change-Id: Ic8c07cc02c80953920f5f86b426a55114ea2cc44

Change-Id: I03986bf2b05032d8a29e5bd629f7f6703269ab13

Use settings from vpx_config.asm

Prefix functions with vpx.

Change-Id: I1091d9b063e9f5af0dce554bb636ee894c05dcf7

Revision a95584945dd9ce3acc66c6cd8f6796bc4404d40d
from git://git.videolan.org/x264.git

Temporarily name file x86inc.asm until all necessary local patches are
applied.

Change-Id: I9c7d0ed4d3ed900ae2d5db0abbcc048a2892c9b8

Currently the prefix is forced to vp9 for any function using
x86inc.asm.

Change-Id: Icbca57ce68a52e743bdd7e9be86cfe8353f274c1

matches the project name and doesn't share a media file extension

Change-Id: I9ad6c0a180e36c41f8fc49120615a070ea792a30

Change-Id: I6802731a4d15feef5ce62993dc505ded55c40f7e