Various improvements regarding the way we print code code comments.

src/x64/lithium-codegen-x64.h

Index: src/x64/lithium-codegen-x64.h
diff --git a/src/x64/lithium-codegen-x64.h b/src/x64/lithium-codegen-x64.h
index a988a7af0cfdc3543f4223f68ad6903027118d8f..2fe277f0742231338162f4ea7f14b0cd88ec6d38 100644
--- a/src/x64/lithium-codegen-x64.h
+++ b/src/x64/lithium-codegen-x64.h
@@ -80,6 +80,15 @@ class LCodeGen BASE_EMBEDDED {
   Heap* heap() const { return isolate()->heap(); }
   Zone* zone() const { return zone_; }
 
+  // TODO(svenpanne) Use this consistently.
+  int LookupDestination(int block_id) const {
+    return chunk()->LookupDestination(block_id);
+  }
+
+  bool IsNextEmittedBlock(int block_id) const {
+    return LookupDestination(block_id) == GetNextEmittedBlock();
+  }
+
   bool NeedsEagerFrame() const {
     return GetStackSlotCount() > 0 ||
         info()->is_non_deferred_calling() ||
@@ -160,9 +169,9 @@ class LCodeGen BASE_EMBEDDED {
 
   LPlatformChunk* chunk() const { return chunk_; }
   Scope* scope() const { return scope_; }
-  HGraph* graph() const { return chunk_->graph(); }
+  HGraph* graph() const { return chunk()->graph(); }
 
-  int GetNextEmittedBlock();
+  int GetNextEmittedBlock() const;
 
   void EmitClassOfTest(Label* if_true,
                        Label* if_false,