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/ADT/DAGDeltaAlgorithmTest.cpp

@@ -22,7 +22,7 @@ class FixedDAGDeltaAlgorithm : public DAGDeltaAlgorithm {
   unsigned NumTests;
 
 protected:
-  virtual bool ExecuteOneTest(const changeset_ty &Changes) {
+  bool ExecuteOneTest(const changeset_ty &Changes) override {
     ++NumTests;
     return std::includes(Changes.begin(), Changes.end(),
                          FailingSet.begin(), FailingSet.end());