ARM64: Fix and improve MacroAssembler::Printf.

src/arm64/assembler-arm64.h

Index: src/arm64/assembler-arm64.h
diff --git a/src/arm64/assembler-arm64.h b/src/arm64/assembler-arm64.h
index a3fbc98d9754a5dfd872ae1cc5f86e9f914c6930..5a28ea6c9e4eff5f11c908ad09361b4a0839b6c9 100644
--- a/src/arm64/assembler-arm64.h
+++ b/src/arm64/assembler-arm64.h
@@ -66,6 +66,7 @@ struct CPURegister {
   bool IsValidFPRegister() const;
   bool IsNone() const;
   bool Is(const CPURegister& other) const;
+  bool Aliases(const CPURegister& other) const;
 
   bool IsZero() const;
   bool IsSP() const;
@@ -561,6 +562,11 @@ class CPURegList {
     return size_in_bits / kBitsPerByte;
   }
 
+  unsigned TotalSizeInBytes() const {
+    ASSERT(IsValid());
+    return RegisterSizeInBytes() * Count();
+  }
+
  private:
   RegList list_;
   unsigned size_;