Isolate/Thread split: Isolate -> Zone for LocationSummary.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 42919)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -587,7 +587,7 @@
   DEFINE_INSTRUCTION_TYPE_CHECK(type)
 
 #define DECLARE_INSTRUCTION_BACKEND()                                          \
-  virtual LocationSummary* MakeLocationSummary(Isolate* isolate,               \
+  virtual LocationSummary* MakeLocationSummary(Zone* zone,                     \
                                                bool optimizing) const;         \
   virtual void EmitNativeCode(FlowGraphCompiler* compiler);                    \
 
@@ -725,15 +725,15 @@
 
   bool HasLocs() const { return locs_ != NULL; }
 
-  virtual LocationSummary* MakeLocationSummary(Isolate* isolate,
+  virtual LocationSummary* MakeLocationSummary(Zone* zone,
                                                bool is_optimizing) const = 0;
 
-  void InitializeLocationSummary(Isolate* isolate, bool optimizing) {
+  void InitializeLocationSummary(Zone* zone, bool optimizing) {
     ASSERT(locs_ == NULL);
-    locs_ = MakeLocationSummary(isolate, optimizing);
+    locs_ = MakeLocationSummary(zone, optimizing);
   }
 
-  static LocationSummary* MakeCallSummary(Isolate* isolate);
+  static LocationSummary* MakeCallSummary(Zone* zone);
 
   virtual void EmitNativeCode(FlowGraphCompiler* compiler) {
     UNIMPLEMENTED();
@@ -8034,8 +8034,7 @@
 
 // Helper macros for platform ports.
 #define DEFINE_UNIMPLEMENTED_INSTRUCTION(Name)                                \
-  LocationSummary* Name::MakeLocationSummary(                                 \
-      Isolate* isolate, bool opt) const {                                     \
+  LocationSummary* Name::MakeLocationSummary(Zone* zone, bool opt) const {    \
     UNIMPLEMENTED();                                                          \
     return NULL;                                                              \
   }                                                                           \