Split HPhase for Lithium and Hydrogen using common CompilationPhase base.

src/lithium.h

Index: src/lithium.h
diff --git a/src/lithium.h b/src/lithium.h
index ab34453beff6015a37dc9a00afc02e4251f93414..416a82417a33c72c559775e2f49e8d34df8eabd3 100644
--- a/src/lithium.h
+++ b/src/lithium.h
@@ -778,6 +778,18 @@ enum NumberUntagDMode {
 };
 
 
+class LPhase : public CompilationPhase {
+ public:
+  LPhase(const char* name, LAllocator* allocator);
+  LPhase(const char* name, LChunk* chunk);
+  ~LPhase();
+
+ private:
+  LAllocator* allocator_;
+  LChunk* chunk_;
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_LITHIUM_H_