[wasm] Int64Lowering of Int64Sub on ia32 and arm.

src/compiler/x87/instruction-selector-x87.cc

Index: src/compiler/x87/instruction-selector-x87.cc
diff --git a/src/compiler/x87/instruction-selector-x87.cc b/src/compiler/x87/instruction-selector-x87.cc
index b43db54668ce344d0b7abe36a5820a69436b08cf..2000525eeff5b597d230ce22c86999c1ecb340d8 100644
--- a/src/compiler/x87/instruction-selector-x87.cc
+++ b/src/compiler/x87/instruction-selector-x87.cc
@@ -562,6 +562,8 @@ void InstructionSelector::VisitInt32PairAdd(Node* node) {
   Emit(kX87AddPair, 2, outputs, 4, inputs, 1, temps);
 }
 
+void InstructionSelector::VisitInt32PairSub(Node* node) { UNIMPLEMENTED(); }
+
 void InstructionSelector::VisitWord32PairShl(Node* node) {
   X87OperandGenerator g(this);