Remove /arch:SSE2 from Win 64 Release builds

gyp/common_conditions.gypi

Index: gyp/common_conditions.gypi
diff --git a/gyp/common_conditions.gypi b/gyp/common_conditions.gypi
index 39e387eb0f2ac6ad23d9ac3ca2178f076d7b5622..7e3f71d68bb3ba10cad5f2c38730e9451c16fd82 100644
--- a/gyp/common_conditions.gypi
+++ b/gyp/common_conditions.gypi
@@ -138,9 +138,21 @@
               },
               'Release_x64': {
                 'inherit_from': ['Release'],
+                'msvs_settings': {
+                  'VCCLCompilerTool': {
+                     # Don't specify /arch. SSE2 is implied by 64bit and specifying it warns.
+                    'EnableEnhancedInstructionSet': '0', #
+                  },
+                },
               },
               'Release_Developer_x64': {
                 'inherit_from': ['Release_Developer'],
+                'msvs_settings': {
+                  'VCCLCompilerTool': {
+                     # Don't specify /arch. SSE2 is implied by 64bit and specifying it warns.
+                    'EnableEnhancedInstructionSet': '0', #
+                  },
+                },
               },
             },
           }],