8075511: Enable -Woverloaded-virtual C++ warning for HotSpot build

Reviewed-by: andrew
Backport-of: 8efb3ab7c1cf0164237c50d60c4cd564b3d6a897

Author: franferrax

hotspot/make/linux/makefiles/gcc.make

@@ -212,7 +212,7 @@ ifeq ($(USE_CLANG), true)
   WARNINGS_ARE_ERRORS += -Wno-return-type -Wno-empty-body
 endif
 
-WARNING_FLAGS = -Wpointer-arith -Wsign-compare -Wundef -Wunused-function -Wunused-value -Wformat=2 -Wreturn-type
+WARNING_FLAGS = -Wpointer-arith -Wsign-compare -Wundef -Wunused-function -Wunused-value -Wformat=2 -Wreturn-type -Woverloaded-virtual
 
 ifeq ($(USE_CLANG),)
   # Since GCC 4.3, -Wconversion has changed its meanings to warn these implicit