Enable optimization of top-level code.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
===================================================================
--- src/arm/lithium-codegen-arm.cc	(revision 10686)
+++ src/arm/lithium-codegen-arm.cc	(working copy)
@@ -2873,6 +2873,16 @@
 }
 
 
+void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
+  __ push(cp);  // The context is the first argument.
+  __ LoadHeapObject(scratch0(), instr->hydrogen()->pairs());
+  __ push(scratch0());
+  __ mov(scratch0(), Operand(Smi::FromInt(instr->hydrogen()->flags())));
+  __ push(scratch0());
+  CallRuntime(Runtime::kDeclareGlobals, 3, instr);
+}
+
+
 void LCodeGen::DoGlobalObject(LGlobalObject* instr) {
   Register result = ToRegister(instr->result());
   __ ldr(result, ContextOperand(cp, Context::GLOBAL_INDEX));