Make sure gcc4.6 is not used

source/libvpx/vp8/encoder/arm/neon/vp8_shortwalsh4x4_neon.c

Index: source/libvpx/vp8/encoder/arm/neon/vp8_shortwalsh4x4_neon.c
===================================================================
--- source/libvpx/vp8/encoder/arm/neon/vp8_shortwalsh4x4_neon.c	(revision 292104)
+++ source/libvpx/vp8/encoder/arm/neon/vp8_shortwalsh4x4_neon.c	(working copy)
@@ -10,10 +10,22 @@
 
 #include <arm_neon.h>
 
+#if (__GNUC__ == 4 && (__GNUC_MINOR__ == 6))
+#warning Using GCC 4.6 is not recommended
+// Some versions of gcc4.6 do not correctly process this function. When built
+// with any gcc4.6, use the C code.
+#include "./vp8_rtcd.h"
 void vp8_short_walsh4x4_neon(
         int16_t *input,
         int16_t *output,
         int pitch) {
+  vp8_short_walsh4x4_c(input, output, pitch);
+}
+#else
+void vp8_short_walsh4x4_neon(
+        int16_t *input,
+        int16_t *output,
+        int pitch) {
     uint16x4_t d16u16;
     int16x8_t q0s16, q1s16;
     int16x4_t dEmptys16, d0s16, d1s16, d2s16, d3s16, d4s16, d5s16, d6s16, d7s16;
@@ -116,3 +128,4 @@
     vst1q_s16(output + 8, q1s16);
     return;
 }
+#endif  // (__GNUC__ == 4 && (__GNUC_MINOR__ == 6))