fft: init functions with INIT_XMM/YMM.

This is required to handle clobbering of XMM registers on Win64
correctly. Fixes FFT and all tests depending on FFT on Win64.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
Signed-off-by: Janne Grunau <janne-libav@jannau.net>

libavcodec/x86/fft_mmx.asm

@@ -639,11 +639,14 @@ cglobal fft_dispatch%3%2, 2,5,8, z, nbits
 %endmacro ; DECL_FFT
 
 %ifdef HAVE_AVX
+INIT_YMM
 DECL_FFT 6, _avx
 DECL_FFT 6, _avx, _interleave
 %endif
+INIT_XMM
 DECL_FFT 5, _sse
 DECL_FFT 5, _sse, _interleave
+INIT_MMX
 DECL_FFT 4, _3dn
 DECL_FFT 4, _3dn, _interleave
 DECL_FFT 4, _3dn2