[ia32] Introduce vex prefix version of float64 arithmetic binop

src/base/cpu.cc

Index: src/base/cpu.cc
diff --git a/src/base/cpu.cc b/src/base/cpu.cc
index db733e4dbdf94cbc34c503fff6ce9660f7bb076a..e188406f1a21ff72226b17c2332eb7ccd942dd49 100644
--- a/src/base/cpu.cc
+++ b/src/base/cpu.cc
@@ -359,7 +359,7 @@ CPU::CPU()
     has_ssse3_ = (cpu_info[2] & 0x00000200) != 0;
     has_sse41_ = (cpu_info[2] & 0x00080000) != 0;
     has_sse42_ = (cpu_info[2] & 0x00100000) != 0;
-    has_avx_ = (cpu_info[2] & 0x18000000) != 0;
+    has_avx_ = (cpu_info[2] & 0x10000000) != 0;
     if (has_avx_) has_fma3_ = (cpu_info[2] & 0x00001000) != 0;
   }