[PATCH] Patched clang to emit x86 blends as shufflevectors.

[Rafael Ávila de Espíndola]

LGTM with a few small requests.

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Comment at: test/CodeGen/avx-builtins.c:118
@@ +117,3 @@
+  // CHECK: shufflevector <4 x double> %{{.*}}, <4 x double> %{{.*}}, <4 x i32> <i32 4, i32 1, i32 2, i32 7>
+  return _mm256_blend_pd(__a, __b, 57);
+}
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Write the constant in hex, so it is easier to read.

57 is 0x39. So, the lower 4 bits are 1001. It would probably be test to use a non symmetrical constant in the test.

http://reviews.llvm.org/D3601