Implement string constructor stub on ARM.

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
===================================================================
--- src/arm/macro-assembler-arm.cc	(revision 5890)
+++ src/arm/macro-assembler-arm.cc	(working copy)
@@ -1693,6 +1693,33 @@
 }
 
 
+void MacroAssembler::LoadGlobalFunction(int index, Register function) {
+  // Load the global or builtins object from the current context.
+  ldr(function, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  // Load the global context from the global or builtins object.
+  ldr(function, FieldMemOperand(function,
+                                GlobalObject::kGlobalContextOffset));
+  // Load the function from the global context.
+  ldr(function, MemOperand(function, Context::SlotOffset(index)));
+}
+
+
+void MacroAssembler::LoadGlobalFunctionInitialMap(Register function,
+                                                  Register map,
+                                                  Register scratch) {
+  // Load the initial map. The global functions all have initial maps.
+  ldr(map, FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
+  if (FLAG_debug_code) {
+    Label ok, fail;
+    CheckMap(map, scratch, Heap::kMetaMapRootIndex, &fail, false);
+    b(&ok);
+    bind(&fail);
+    Abort("Global functions must have initial map");
+    bind(&ok);
+  }
+}
+
+
 void MacroAssembler::JumpIfNotBothSmi(Register reg1,
                                       Register reg2,
                                       Label* on_not_both_smi) {