message: Ruy: Fix to x86 AVX2 float pack.
diff: @@ -711,7 +711,7 @@ inline void PackFloatAvx2Packer(const float* src_ptr, const float* zerobuf,
  r2 = _mm256_permute2f128_ps(t2, t6, 0x20);
  r6 = _mm256_permute2f128_ps(t3, t7, 0x20);
  r3 = _mm256_permute2f128_ps(t2, t6, 0x31);
  - r7 = _mm256_permute2f128_ps(t3, t7, 0x31);
  + // r7 no longer needed.
  _mm256_storeu_ps(trailing_buf + 0 * 8, r0);
  _mm256_storeu_ps(trailing_buf + 2 * 8, r4);
  @@ -720,7 +720,7 @@ inline void PackFloatAvx2Packer(const float* src_ptr, const float* zerobuf,
  _mm256_storeu_ps(trailing_buf + 1 * 8, r2);
  _mm256_storeu_ps(trailing_buf + 3 * 8, r6);
  _mm256_storeu_ps(trailing_buf + 5 * 8, r3);
  - _mm256_storeu_ps(trailing_buf + 7 * 8, r7);
  + // No store to (trailing_buf + 7 * 8), space not allocated.
  }
  packed_ptr += kPackRows * kPackCols;
  