Use 'override/final' instead of 'virtual' for overridden methods

The patch is generated using clang-tidy misc-use-override check.

This command was used:

  tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py \
    -checks='-*,misc-use-override' -header-filter='llvm|clang' \
    -j=32 -fix -format

http://reviews.llvm.org/D8925



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234679 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/Support/CommandLineTest.cpp

@@ -65,9 +65,7 @@ public:
   StackOption(const M0t &M0, const M1t &M1, const M2t &M2, const M3t &M3)
     : Base(M0, M1, M2, M3) {}
 
-  ~StackOption() {
-    this->removeArgument();
-  }
+  ~StackOption() override { this->removeArgument(); }
 };