VM: Improve generated code for loading the current context.

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
===================================================================
--- runtime/vm/intermediate_language.cc	(revision 40882)
+++ runtime/vm/intermediate_language.cc	(working copy)
@@ -2622,6 +2622,21 @@
 }
 
 
+LocationSummary* CurrentContextInstr::MakeLocationSummary(Isolate* isolate,
+                                                          bool opt) const {
+  return LocationSummary::Make(isolate,
+                               0,
+                               Location::RegisterLocation(CTX),
+                               LocationSummary::kNoCall);
+}
+
+
+void CurrentContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  // No code to emit. Just assert the correct result register.
+  ASSERT(locs()->out(0).reg() == CTX);
+}
+
+
 LocationSummary* StoreContextInstr::MakeLocationSummary(Isolate* isolate,
                                                         bool optimizing) const {
   const intptr_t kNumInputs = 1;
@@ -2633,6 +2648,12 @@
 }
 
 
+void StoreContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  // Nothing to do.  Context register was loaded by the register allocator.
+  ASSERT(locs()->in(0).reg() == CTX);
+}
+
+
 LocationSummary* PushTempInstr::MakeLocationSummary(Isolate* isolate,
                                                     bool optimizing) const {
   return LocationSummary::Make(isolate,
@@ -2670,12 +2691,6 @@
 }
 
 
-void StoreContextInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  // Nothing to do.  Context register was loaded by the register allocator.
-  ASSERT(locs()->in(0).reg() == CTX);
-}
-
-
 StrictCompareInstr::StrictCompareInstr(intptr_t token_pos,
                                        Token::Kind kind,
                                        Value* left,