lpc_mmx: add xmm registers to clobber list

Originally committed as revision 25620 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/x86/lpc_mmx.c

@@ -62,6 +62,8 @@ static void apply_welch_window_sse2(const int32_t *data, int len, double *w_data
         "3:                                    \n\t"
         :"+&r"(i), "+&r"(j)
         :"r"(w_data+n2), "r"(data+n2), "m"(c), "r"(len)
+         XMM_CLOBBERS_ONLY("%xmm0", "%xmm1", "%xmm2", "%xmm3",
+                                    "%xmm5", "%xmm6", "%xmm7")
     );
 #undef WELCH
 }