Turn StringLengthStub (used by string wrappers only) into a hydrogen stub.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 558f5e17061a905db1bb2edfb39ff6001eed00bb..081bb900ba216dfe05abf8cf9068429bb5dc6928 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -165,6 +165,26 @@ void KeyedLoadFieldStub::InitializeInterfaceDescriptor(
 }
 
 
+void StringLengthStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { r0, r2 };
+  descriptor->register_param_count_ = 2;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ = NULL;
+}
+
+
+void KeyedStringLengthStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { r1, r0 };
+  descriptor->register_param_count_ = 2;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ = NULL;
+}
+
+
 void KeyedStoreFastElementStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
@@ -2099,37 +2119,6 @@ void FunctionPrototypeStub::Generate(MacroAssembler* masm) {
 }
 
 
-void StringLengthStub::Generate(MacroAssembler* masm) {
-  Label miss;
-  Register receiver;
-  if (kind() == Code::KEYED_LOAD_IC) {
-    // ----------- S t a t e -------------
-    //  -- lr    : return address
-    //  -- r0    : key
-    //  -- r1    : receiver
-    // -----------------------------------
-    __ cmp(r0, Operand(masm->isolate()->factory()->length_string()));
-    __ b(ne, &miss);
-    receiver = r1;
-  } else {
-    ASSERT(kind() == Code::LOAD_IC);
-    // ----------- S t a t e -------------
-    //  -- r2    : name
-    //  -- lr    : return address
-    //  -- r0    : receiver
-    //  -- sp[0] : receiver
-    // -----------------------------------
-    receiver = r0;
-  }
-
-  StubCompiler::GenerateLoadStringLength(masm, receiver, r3, r4, &miss);
-
-  __ bind(&miss);
-  StubCompiler::TailCallBuiltin(
-      masm, BaseLoadStoreStubCompiler::MissBuiltin(kind()));
-}
-
-
 void StoreArrayLengthStub::Generate(MacroAssembler* masm) {
   // This accepts as a receiver anything JSArray::SetElementsLength accepts
   // (currently anything except for external arrays which means anything with