[wasm] Int64Lowering of Int64Sub on ia32 and arm.

src/compiler/raw-machine-assembler.h

Index: src/compiler/raw-machine-assembler.h
diff --git a/src/compiler/raw-machine-assembler.h b/src/compiler/raw-machine-assembler.h
index ee4d109f3c8b321f9c809d7b2d061c58f7520bf1..dc35bca98e296ced46ae67a6869dcaff8ecbae66 100644
--- a/src/compiler/raw-machine-assembler.h
+++ b/src/compiler/raw-machine-assembler.h
@@ -327,6 +327,9 @@ class RawMachineAssembler {
   Node* Int32PairAdd(Node* a_low, Node* a_high, Node* b_low, Node* b_high) {
     return AddNode(machine()->Int32PairAdd(), a_low, a_high, b_low, b_high);
   }
+  Node* Int32PairSub(Node* a_low, Node* a_high, Node* b_low, Node* b_high) {
+    return AddNode(machine()->Int32PairSub(), a_low, a_high, b_low, b_high);
+  }
   Node* Word32PairShl(Node* low_word, Node* high_word, Node* shift) {
     return AddNode(machine()->Word32PairShl(), low_word, high_word, shift);
   }