x86_64: Enable core.oat/boot.oat compilation

This patch enabled compilation of image.

Change-Id: Idacce4a3898964d3a05762925dba236d7254a254
Signed-off-by: Dmitry Petrochenko <dmitry.petrochenko@intel.com>
diff --git a/dex2oat/dex2oat.cc b/dex2oat/dex2oat.cc
index c3f2082..7ffab69 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -1093,8 +1093,7 @@
   }
 
   if (compiler_filter_string == nullptr) {
-    if ((instruction_set == kX86_64 && image) ||
-        instruction_set == kArm64 ||
+    if (instruction_set == kArm64 ||
         instruction_set == kMips) {
       // TODO: implement/fix compilers for these architectures.
       compiler_filter_string = "interpret-only";