Remove superfluous 'virtual' specifiers in ART.

Remove 'virtual' specifier on methods already bearing the 'override'
specifier.

Test: mmma art
Change-Id: I114930969a5ca048d88de9ecd18e2c6403593e31
diff --git a/compiler/utils/jni_macro_assembler.h b/compiler/utils/jni_macro_assembler.h
index e0c2992..e6130cf 100644
--- a/compiler/utils/jni_macro_assembler.h
+++ b/compiler/utils/jni_macro_assembler.h
@@ -299,7 +299,7 @@
   JNIMacroLabelCommon() : JNIMacroLabel(kIsa) {
   }
 
-  virtual ~JNIMacroLabelCommon() override {}
+  ~JNIMacroLabelCommon() override {}
 
  private:
   PlatformLabel label_;
diff --git a/compiler/utils/x86/jni_macro_assembler_x86.cc b/compiler/utils/x86/jni_macro_assembler_x86.cc
index df946bd..540d72b 100644
--- a/compiler/utils/x86/jni_macro_assembler_x86.cc
+++ b/compiler/utils/x86/jni_macro_assembler_x86.cc
@@ -28,7 +28,7 @@
 class X86ExceptionSlowPath final : public SlowPath {
  public:
   explicit X86ExceptionSlowPath(size_t stack_adjust) : stack_adjust_(stack_adjust) {}
-  virtual void Emit(Assembler *sp_asm) override;
+  void Emit(Assembler *sp_asm) override;
  private:
   const size_t stack_adjust_;
 };
diff --git a/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc b/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc
index d5c0878..5924a8b 100644
--- a/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc
+++ b/compiler/utils/x86_64/jni_macro_assembler_x86_64.cc
@@ -577,7 +577,7 @@
 class X86_64ExceptionSlowPath final : public SlowPath {
  public:
   explicit X86_64ExceptionSlowPath(size_t stack_adjust) : stack_adjust_(stack_adjust) {}
-  virtual void Emit(Assembler *sp_asm) override;
+  void Emit(Assembler *sp_asm) override;
  private:
   const size_t stack_adjust_;
 };
diff --git a/compiler/utils/x86_64/jni_macro_assembler_x86_64.h b/compiler/utils/x86_64/jni_macro_assembler_x86_64.h
index 4411558..465ebbe 100644
--- a/compiler/utils/x86_64/jni_macro_assembler_x86_64.h
+++ b/compiler/utils/x86_64/jni_macro_assembler_x86_64.h
@@ -165,7 +165,7 @@
                               bool null_allowed) override;
 
   // src holds a handle scope entry (Object**) load this into dst
-  virtual void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) override;
+  void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) override;
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
   // know that src may not be null.