Use 'final' and 'override' specifiers directly in ART.

Remove all uses of macros 'FINAL' and 'OVERRIDE' and replace them with
'final' and 'override' specifiers. Remove all definitions of these
macros as well, which were located in these files:
- libartbase/base/macros.h
- test/913-heaps/heaps.cc
- test/ti-agent/ti_macros.h

ART is now using C++14; the 'final' and 'override' specifiers have
been introduced in C++11.

Test: mmma art
Change-Id: I256c7758155a71a2940ef2574925a44076feeebf
diff --git a/compiler/compiled_method.h b/compiler/compiled_method.h
index f880280..864ce58 100644
--- a/compiler/compiled_method.h
+++ b/compiler/compiled_method.h
@@ -104,7 +104,7 @@
   uint32_t packed_fields_;
 };
 
-class CompiledMethod FINAL : public CompiledCode {
+class CompiledMethod final : public CompiledCode {
  public:
   // Constructs a CompiledMethod.
   // Note: Consider using the static allocation methods below that will allocate the CompiledMethod