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

lib/Support/CommandLine.cpp

@@ -784,7 +784,7 @@ class StrDupSaver : public StringSaver {
   std::vector<char *> Dups;
 
 public:
-  ~StrDupSaver() {
+  ~StrDupSaver() override {
     for (std::vector<char *>::iterator I = Dups.begin(), E = Dups.end(); I != E;
          ++I) {
       char *Dup = *I;