[wasm] Int64Lowering of Int64Add 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 e0d622891892d0a9e377793be778cde0e201228d..0e8f30c3bfe8e617351b96ece4ef37cb95e1a83c 100644
--- a/src/compiler/arm/instruction-selector-arm.cc
+++ b/src/compiler/arm/instruction-selector-arm.cc
@@ -767,6 +767,22 @@ void InstructionSelector::VisitWord32Sar(Node* node) {
   VisitShift(this, node, TryMatchASR);
 }
 
+void InstructionSelector::VisitInt32PairAdd(Node* node) {
+  ArmOperandGenerator g(this);
+
+  // We use UseUniqueRegister here to avoid register sharing with the output
+  // registers.
+  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(kArmAddPair, 2, outputs, 4, inputs);
+}
+
 void InstructionSelector::VisitWord32PairShl(Node* node) {
   ArmOperandGenerator g(this);
   Int32Matcher m(node->InputAt(2));