Source release 15.1.0

platforms/x86-64/settings.gypi

@@ -45,6 +45,7 @@
       '-Wshadow',
       '-Wnon-virtual-dtor',
       #'-Woverloaded-virtual',
+      #'-Wsuggest-override',
       #'-Wctor-dtor-privacy',
       '-Wcast-align',
       '-Wno-conversion',
@@ -54,7 +55,6 @@
       #'-Wuseless-cast',
       '-Wno-unused-parameter',   # repeated in protobufs triggers this
       '-Wno-unused-local-typedefs',  # metrics requires this
-      '-Wno-inconsistent-missing-override',
       #'-Wno-maybe-uninitialized',
       '-Wno-unknown-warning-option',
       '-Wno-dangling-else',  # Allowed by Google C++ Style