More reduction of accessing TLS by caching/passing isolate value.

runtime/vm/deopt_instructions.h

Index: runtime/vm/deopt_instructions.h
===================================================================
--- runtime/vm/deopt_instructions.h	(revision 36586)
+++ runtime/vm/deopt_instructions.h	(working copy)
@@ -295,7 +295,7 @@
 // the heap and reset the builder's internal state for the next DeoptInfo.
 class DeoptInfoBuilder : public ValueObject {
  public:
-  explicit DeoptInfoBuilder(const intptr_t num_args);
+  DeoptInfoBuilder(Isolate* isolate, const intptr_t num_args);
 
   // 'object_table' holds all objects referred to by DeoptInstr in
   // all DeoptInfo instances for a single Code object.
@@ -350,6 +350,10 @@
 
   void AddConstant(const Object& obj, intptr_t dest_index);
 
+  Isolate* isolate() const { return isolate_; }
+
+  Isolate* isolate_;
+
   GrowableArray<DeoptInstr*> instructions_;
   const GrowableObjectArray& object_table_;
   const intptr_t num_args_;