volatile -> const, where possible

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
===================================================================
--- runtime/vm/compiler.cc	(revision 44732)
+++ runtime/vm/compiler.cc	(working copy)
@@ -178,7 +178,7 @@
 
 
 RawError* Compiler::Compile(const Library& library, const Script& script) {
-  Isolate* volatile isolate = Isolate::Current();
+  Isolate* const isolate = Isolate::Current();
   StackZone zone(isolate);
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {
@@ -279,7 +279,7 @@
     }
   }
 
-  Isolate* volatile isolate = Isolate::Current();
+  Isolate* const isolate = Isolate::Current();
   // We remember all the classes that are being compiled in these lists. This
   // also allows us to reset the marked_for_parsing state in case we see an
   // error.
@@ -374,9 +374,9 @@
   }
   TimerScope timer(FLAG_compiler_stats, &CompilerStats::codegen_timer);
   bool is_compiled = false;
-  Thread* volatile thread = Thread::Current();
-  Zone* volatile zone = thread->zone();
-  Isolate* volatile isolate = thread->isolate();
+  Thread* const thread = Thread::Current();
+  Zone* const zone = thread->zone();
+  Isolate* const isolate = thread->isolate();
   HANDLESCOPE(isolate);
 
   // We may reattempt compilation if the function needs to be assembled using
@@ -964,10 +964,10 @@
                                        const Function& function,
                                        bool optimized,
                                        intptr_t osr_id) {
-  Thread* volatile thread = Thread::Current();
-  Isolate* volatile isolate = thread->isolate();
+  Thread* const thread = Thread::Current();
+  Isolate* const isolate = thread->isolate();
   StackZone stack_zone(isolate);
-  Zone* volatile zone = stack_zone.GetZone();
+  Zone* const zone = stack_zone.GetZone();
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {
     TIMERSCOPE(isolate, time_compilation);
@@ -1065,7 +1065,7 @@
 // This is only used from unit tests.
 RawError* Compiler::CompileParsedFunction(
     ParsedFunction* parsed_function) {
-  Isolate* volatile isolate = Isolate::Current();
+  Isolate* const isolate = Isolate::Current();
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {
     // Non-optimized code generator.
@@ -1142,7 +1142,7 @@
   // The VM sets the field's value to transiton_sentinel prior to
   // evaluating the initializer value.
   ASSERT(field.value() == Object::transition_sentinel().raw());
-  Isolate* volatile isolate = Isolate::Current();
+  Isolate* const isolate = Isolate::Current();
   StackZone zone(isolate);
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {
@@ -1175,8 +1175,8 @@
 
 
 RawObject* Compiler::ExecuteOnce(SequenceNode* fragment) {
-  Thread* volatile thread = Thread::Current();
-  Isolate* volatile isolate = thread->isolate();
+  Thread* const thread = Thread::Current();
+  Isolate* const isolate = thread->isolate();
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {
     if (FLAG_trace_compiler) {