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

src/code-stub-assembler.h

Index: src/code-stub-assembler.h
diff --git a/src/code-stub-assembler.h b/src/code-stub-assembler.h
index fa5ba934f0d9a9278f599c5dae2edddb812d3d23..650b51ffff0ab1593ded8448099244f781fa2b50 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -853,6 +853,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
 
   // Convert any object to a String.
   Node* ToString(Node* context, Node* input);
+  Node* ToString_Inline(Node* const context, Node* const input);
 
   // Convert any object to a Primitive.
   Node* JSReceiverToPrimitive(Node* context, Node* input);
@@ -868,6 +869,9 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   // ES6 7.1.15 ToLength, but jumps to range_error if the result is not a Smi.
   Node* ToSmiLength(Node* input, Node* const context, Label* range_error);
 
+  // ES6 7.1.15 ToLength, but with inlined fast path.
+  Node* ToLength_Inline(Node* const context, Node* const input);
+
   // Convert any object to an Integer.
   Node* ToInteger(Node* context, Node* input,
                   ToIntegerTruncationMode mode = kNoTruncation);