[turbofan] Add comments to CodeAssembler

src/compiler/arm64/code-generator-arm64.cc

Index: src/compiler/arm64/code-generator-arm64.cc
diff --git a/src/compiler/arm64/code-generator-arm64.cc b/src/compiler/arm64/code-generator-arm64.cc
index 14603863b18c7ff074d3d99966421b84ce5dd00d..ca35008cac954849bf269099e02ba5081de2231a 100644
--- a/src/compiler/arm64/code-generator-arm64.cc
+++ b/src/compiler/arm64/code-generator-arm64.cc
@@ -714,6 +714,11 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArchDebugBreak:
       __ Debug("kArchDebugBreak", 0, BREAK);
       break;
+    case kArchComment: {
+      Address comment_string = i.InputExternalReference(0).address();
+      __ RecordComment(reinterpret_cast<const char*>(comment_string));
+      break;
+    }
     case kArchNop:
     case kArchThrowTerminator:
       // don't emit code for nops.