Convert CurrentContext and StoreContext to locations code generation scheme

runtime/vm/flow_graph_compiler_x64.cc

Index: runtime/vm/flow_graph_compiler_x64.cc
diff --git a/runtime/vm/flow_graph_compiler_x64.cc b/runtime/vm/flow_graph_compiler_x64.cc
index 4d5fa51cb13fd0f8bbef4f7bb5ee19efce76789e..68d5425f2b731ee379fb196df1d774778911f518 100644
--- a/runtime/vm/flow_graph_compiler_x64.cc
+++ b/runtime/vm/flow_graph_compiler_x64.cc
@@ -589,12 +589,14 @@ void FlowGraphCompiler::EmitStaticCall(intptr_t token_index,
 
 
 void FlowGraphCompiler::VisitCurrentContext(CurrentContextComp* comp) {
-  __ movq(RAX, CTX);
+  // Moved to intermediate_language_x64.cc.
+  UNREACHABLE();
 }
 
 
 void FlowGraphCompiler::VisitStoreContext(StoreContextComp* comp) {
-  LoadValue(CTX, comp->value());
+  // Moved to intermediate_language_x64.cc.
+  UNREACHABLE();
 }