[cleanup] Fix missing overrides on virtual functions

Add overrides to port specific assemblers and delete redundant empty
override.

Bug: v8:9810
Change-Id: I17e4614e06783867ae50e87bba83d35ebc9d0b51
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1862567
Auto-Submit: Dan Elphick <delphick@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64297}

src/codegen/arm/assembler-arm.h

@@ -306,9 +306,9 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   explicit Assembler(const AssemblerOptions&,
                      std::unique_ptr<AssemblerBuffer> = {});
 
-  virtual ~Assembler();
+  ~Assembler() override;
 
-  virtual void AbortedCodeGeneration() { pending_32_bit_constants_.clear(); }
+  void AbortedCodeGeneration() override { pending_32_bit_constants_.clear(); }
 
   // GetCode emits any pending (non-emitted) code and fills the descriptor desc.
   static constexpr int kNoHandlerTable = 0;

src/codegen/arm64/assembler-arm64.h

@@ -193,9 +193,9 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   explicit Assembler(const AssemblerOptions&,
                      std::unique_ptr<AssemblerBuffer> = {});
 
-  virtual ~Assembler();
+  ~Assembler() override;
 
-  virtual void AbortedCodeGeneration();
+  void AbortedCodeGeneration() override;
 
   // System functions ---------------------------------------------------------
   // Start generating code from the beginning of the buffer, discarding any code

src/codegen/ia32/assembler-ia32.h

@@ -372,7 +372,6 @@ class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
   // own buffer. Otherwise it takes ownership of the provided buffer.
   explicit Assembler(const AssemblerOptions&,
                      std::unique_ptr<AssemblerBuffer> = {});
-  virtual ~Assembler() {}
 
   // GetCode emits any pending (non-emitted) code and fills the descriptor desc.
   static constexpr int kNoHandlerTable = 0;