[wasm] Int64Lowering of Int64Sub on ia32 and arm.

src/compiler/arm/instruction-selector-arm.cc

Index: src/compiler/arm/instruction-selector-arm.cc
diff --git a/src/compiler/arm/instruction-selector-arm.cc b/src/compiler/arm/instruction-selector-arm.cc
index fa5f2151cd91b6edee808ec222f4237eb1b70f99..40b92339c4019f9141bba5c73289811f7ee67d51 100644
--- a/src/compiler/arm/instruction-selector-arm.cc
+++ b/src/compiler/arm/instruction-selector-arm.cc
@@ -784,6 +784,22 @@ void InstructionSelector::VisitInt32PairAdd(Node* node) {
   Emit(kArmAddPair, 2, outputs, 4, inputs);
 }
 
+void InstructionSelector::VisitInt32PairSub(Node* node) {
+  ArmOperandGenerator g(this);
+
+  // We use UseUniqueRegister here to avoid register sharing with the output
+  // register.
+  InstructionOperand inputs[] = {
+      g.UseRegister(node->InputAt(0)), g.UseUniqueRegister(node->InputAt(1)),
+      g.UseRegister(node->InputAt(2)), g.UseUniqueRegister(node->InputAt(3))};
+
+  InstructionOperand outputs[] = {
+      g.DefineAsRegister(node),
+      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
+
+  Emit(kArmSubPair, 2, outputs, 4, inputs);
+}
+
 void InstructionSelector::VisitWord32PairShl(Node* node) {
   ArmOperandGenerator g(this);
   Int32Matcher m(node->InputAt(2));