[turbofan] move label generation to code generator

src/compiler/code-generator.h

Index: src/compiler/code-generator.h
diff --git a/src/compiler/code-generator.h b/src/compiler/code-generator.h
index 2184a8405d5757993010ca8ab68aaecf4d78e565..b03e2add31192a19d8fe33d571f5e4c5555558a7 100644
--- a/src/compiler/code-generator.h
+++ b/src/compiler/code-generator.h
@@ -33,6 +33,8 @@ class CodeGenerator FINAL : public GapResolver::Assembler {
   Isolate* isolate() const { return zone()->isolate(); }
   Linkage* linkage() const { return linkage_; }
 
+  Label* GetLabel(BasicBlock::RpoNumber rpo) { return &labels_[rpo.ToSize()]; }
+
  private:
   MacroAssembler* masm() { return &masm_; }
   GapResolver* resolver() { return &resolver_; }
@@ -122,6 +124,7 @@ class CodeGenerator FINAL : public GapResolver::Assembler {
   Linkage* const linkage_;
   InstructionSequence* const code_;
   CompilationInfo* const info_;
+  Label* const labels_;
   BasicBlock::RpoNumber current_block_;
   SourcePosition current_source_position_;
   MacroAssembler masm_;