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

llvm-svn: 234679
diff --git a/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp b/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
index 23173bf..84400f8 100644
--- a/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
+++ b/llvm/lib/Target/SystemZ/Disassembler/SystemZDisassembler.cpp
@@ -25,7 +25,7 @@
 public:
   SystemZDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx)
     : MCDisassembler(STI, Ctx) {}
-  virtual ~SystemZDisassembler() {}
+  ~SystemZDisassembler() override {}
 
   DecodeStatus getInstruction(MCInst &instr, uint64_t &Size,
                               ArrayRef<uint8_t> Bytes, uint64_t Address,