Generate smaller unoptimized code for certain expressions.

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
===================================================================
--- runtime/vm/intermediate_language.cc	(revision 33576)
+++ runtime/vm/intermediate_language.cc	(working copy)
@@ -2062,17 +2062,20 @@
 
 
 LocationSummary* DropTempsInstr::MakeLocationSummary(bool optimizing) const {
-  return LocationSummary::Make(1,
-                               Location::SameAsFirstInput(),
-                               LocationSummary::kNoCall);
+  return (InputCount() != 0)
+      ? LocationSummary::Make(1,
+                              Location::SameAsFirstInput(),
+                              LocationSummary::kNoCall)
+      : LocationSummary::Make(0,
+                              Location::NoLocation(),
+                              LocationSummary::kNoCall);
 }
 
 
 void DropTempsInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(!compiler->is_optimizing());
-  Register value = locs()->in(0).reg();
-  Register result = locs()->out().reg();
-  ASSERT(result == value);  // Assert that register assignment is correct.
+  // Assert that register assignment is correct.
+  ASSERT((InputCount() == 0) || locs()->out().reg() == locs()->in(0).reg());
   __ Drop(num_temps());
 }