generates a stub function when the specific architecture is not enabled,
exposing a symbol in the module, avoiding a compiler warning
Change-Id: Ia9336e57466a9b5241b85c1c95838e91c9283147
move the attribute to the front of the function to quiet clang warning:
GCC does not allow no_sanitize_thread attribute in this position on a
function definition
Change-Id: Ie4cc6e35a07bd00eab67d9cd6801bd2be9cfe676
Split initialization of YUV444Converters[] out of Upsamplers init.
update test for NULL function pointers
Change-Id: I9603f54250f90c85a12ffbecfd6c59e9b06c47e0