[csa] Add ToLength and ToString variants with inlined fast checks

src/code-stub-assembler.cc

Index: src/code-stub-assembler.cc
diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index 79d2b7324a51e446b8d0a6e32a3a70d3136d45dc..1cfb70d7a5c22340d799b60bd39bdef69441c91e 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -4467,6 +4467,22 @@ Node* CodeStubAssembler::ToString(Node* context, Node* input) {
   return result.value();
 }
 
+Node* CodeStubAssembler::ToString_Inline(Node* const context,
+                                         Node* const input) {
+  VARIABLE(var_result, MachineRepresentation::kTagged, input);
+  Label stub_call(this, Label::kDeferred), out(this);
+
+  GotoIf(TaggedIsSmi(input), &stub_call);
+  Branch(IsString(input), &out, &stub_call);
+
+  BIND(&stub_call);
+  var_result.Bind(CallBuiltin(Builtins::kToString, context, input));
+  Goto(&out);
+
+  BIND(&out);
+  return var_result.value();
+}
+
 Node* CodeStubAssembler::JSReceiverToPrimitive(Node* context, Node* input) {
   Label if_isreceiver(this, Label::kDeferred), if_isnotreceiver(this);
   VARIABLE(result, MachineRepresentation::kTagged);
@@ -4544,6 +4560,15 @@ Node* CodeStubAssembler::ToSmiLength(Node* input, Node* const context,
   return result.value();
 }
 
+Node* CodeStubAssembler::ToLength_Inline(Node* const context,
+                                         Node* const input) {
+  Node* const smi_zero = SmiConstant(0);
+  return Select(
+      TaggedIsSmi(input), [=] { return SmiMax(input, smi_zero); },
+      [=] { return CallBuiltin(Builtins::kToLength, context, input); },
+      MachineRepresentation::kTagged);
+}
+
 Node* CodeStubAssembler::ToInteger(Node* context, Node* input,
                                    ToIntegerTruncationMode mode) {
   // We might need to loop once for ToNumber conversion.