[runtime] Port simple String.prototype.indexOf cases to TF Builtin

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 4086100e0875572fe42664e06709d6759af4af5d..19ccf7f084cbdd016d02b2c3f7b74f25b48cdd33 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -139,7 +139,10 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   Node* IntPtrSubFoldConstants(Node* left, Node* right);
   // Round the 32bits payload of the provided word up to the next power of two.
   Node* IntPtrRoundUpToPowerOfTwo32(Node* value);
+  // Select the maximum of the two provided IntPtr values.
   Node* IntPtrMax(Node* left, Node* right);
+  // Select the minimum of the two provided IntPtr values.
+  Node* IntPtrMin(Node* left, Node* right);
 
   // Float64 operations.
   Node* Float64Ceil(Node* x);