[csa] Re-introduce automatic constant folding for IntPtrAdd and IntPtrSub

src/compiler/code-assembler.h

Index: src/compiler/code-assembler.h
diff --git a/src/compiler/code-assembler.h b/src/compiler/code-assembler.h
index 98192330b62f238cfb9a1692d37204f1fee69bc6..ccf9357f56a572fdd85fbe636efc4fca9c384ad1 100644
--- a/src/compiler/code-assembler.h
+++ b/src/compiler/code-assembler.h
@@ -85,9 +85,7 @@ typedef ZoneList<CodeAssemblerVariable*> CodeAssemblerVariableList;
   V(Float64Pow)                            \
   V(Float64InsertLowWord32)                \
   V(Float64InsertHighWord32)               \
-  V(IntPtrAdd)                             \
   V(IntPtrAddWithOverflow)                 \
-  V(IntPtrSub)                             \
   V(IntPtrSubWithOverflow)                 \
   V(IntPtrMul)                             \
   V(Int32Add)                              \
@@ -276,6 +274,9 @@ class V8_EXPORT_PRIVATE CodeAssembler {
   CODE_ASSEMBLER_BINARY_OP_LIST(DECLARE_CODE_ASSEMBLER_BINARY_OP)
 #undef DECLARE_CODE_ASSEMBLER_BINARY_OP
 
+  Node* IntPtrAdd(Node* left, Node* right);
+  Node* IntPtrSub(Node* left, Node* right);
+
   Node* WordShl(Node* value, int shift);
   Node* WordShr(Node* value, int shift);
   Node* Word32Shr(Node* value, int shift);