Support immediate and memory operands for PushArgumentInstr in optimized code.

runtime/vm/locations.cc

Index: runtime/vm/locations.cc
===================================================================
--- runtime/vm/locations.cc	(revision 16802)
+++ runtime/vm/locations.cc	(working copy)
@@ -4,6 +4,7 @@
 
 #include "vm/locations.h"
 
+#include "vm/assembler.h"
 #include "vm/il_printer.h"
 #include "vm/intermediate_language.h"
 #include "vm/flow_graph_compiler.h"
@@ -77,6 +78,19 @@
 }
 
 
+Address Location::ToStackSlotAddress() const {
+  const intptr_t index = stack_index();
+  if (index < 0) {
+    const intptr_t offset = (1 - index)  * kWordSize;
+    return Address(FPREG, offset);
+  } else {
+    const intptr_t offset =
+        (ParsedFunction::kFirstLocalSlotIndex - index) * kWordSize;
+    return Address(FPREG, offset);
+  }
+}
+
+
 const char* Location::Name() const {
   switch (kind()) {
     case kInvalid: return "?";