[cleanup] Minor cleanups concerning assemblers and code generation.

src/compiler/x64/code-generator-x64.cc

Index: src/compiler/x64/code-generator-x64.cc
diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index f62f0ce9880a3afe8e6f143e07c69d25a76d0d43..72dc78f24b53cf3c1a30d95bb3b85b071dc38873 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -762,7 +762,7 @@ void CodeGenerator::AssemblePopArgumentsAdaptorFrame(Register args_reg,
 
 namespace {
 
-void AdjustStackPointerForTailCall(MacroAssembler* masm,
+void AdjustStackPointerForTailCall(Assembler* assembler,
                                    FrameAccessState* state,
                                    int new_slot_above_sp,
                                    bool allow_shrinkage = true) {
@@ -770,10 +770,10 @@ void AdjustStackPointerForTailCall(MacroAssembler* masm,
                           StandardFrameConstants::kFixedSlotCountAboveFp;
   int stack_slot_delta = new_slot_above_sp - current_sp_offset;
   if (stack_slot_delta > 0) {
-    masm->subq(rsp, Immediate(stack_slot_delta * kPointerSize));
+    assembler->subq(rsp, Immediate(stack_slot_delta * kPointerSize));
     state->IncreaseSPDelta(stack_slot_delta);
   } else if (allow_shrinkage && stack_slot_delta < 0) {
-    masm->addq(rsp, Immediate(-stack_slot_delta * kPointerSize));
+    assembler->addq(rsp, Immediate(-stack_slot_delta * kPointerSize));
     state->IncreaseSPDelta(stack_slot_delta);
   }
 }