[builtins] Create StringToNumber helper.

src/builtins/builtins-conversion.cc

Index: src/builtins/builtins-conversion.cc
diff --git a/src/builtins/builtins-conversion.cc b/src/builtins/builtins-conversion.cc
index 0d04a02e241132e87aaea3ffb17add337002e901..625ad87f7623a293d36b71ed1b518578691688cb 100644
--- a/src/builtins/builtins-conversion.cc
+++ b/src/builtins/builtins-conversion.cc
@@ -110,35 +110,13 @@ void Builtins::Generate_NonPrimitiveToPrimitive_String(
 }
 
 void Builtins::Generate_StringToNumber(CodeStubAssembler* assembler) {
-  typedef CodeStubAssembler::Label Label;
   typedef compiler::Node Node;
   typedef TypeConversionDescriptor Descriptor;
 
   Node* input = assembler->Parameter(Descriptor::kArgument);
   Node* context = assembler->Parameter(Descriptor::kContext);
 
-  Label runtime(assembler);
-
-  // Check if string has a cached array index.
-  Node* hash = assembler->LoadNameHashField(input);
-  Node* bit = assembler->Word32And(
-      hash, assembler->Int32Constant(String::kContainsCachedArrayIndexMask));
-  assembler->GotoIf(assembler->Word32NotEqual(bit, assembler->Int32Constant(0)),
-                    &runtime);
-
-  assembler->Return(assembler->SmiTag(
-      assembler->BitFieldDecode<String::ArrayIndexValueBits>(hash)));
-
-  assembler->Bind(&runtime);
-  {
-    // Note: We cannot tail call to the runtime here, as js-to-wasm
-    // trampolines also use this code currently, and they declare all
-    // outgoing parameters as untagged, while we would push a tagged
-    // object here.
-    Node* result =
-        assembler->CallRuntime(Runtime::kStringToNumber, context, input);
-    assembler->Return(result);
-  }
+  assembler->Return(assembler->StringToNumber(context, input));
 }
 
 // ES6 section 7.1.3 ToNumber ( argument )
@@ -183,9 +161,7 @@ void Builtins::Generate_NonNumberToNumber(CodeStubAssembler* assembler) {
     assembler->Bind(&if_inputisstring);
     {
       // The {input} is a String, use the fast stub to convert it to a Number.
-      // TODO(bmeurer): Consider inlining the StringToNumber logic here.
-      Callable callable = CodeFactory::StringToNumber(assembler->isolate());
-      assembler->TailCallStub(callable, context, input);
+      assembler->Return(assembler->StringToNumber(context, input));
     }
 
     assembler->Bind(&if_inputisoddball);