[wasm] Int64Lowering of Int64Sub on ia32 and arm.

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

Index: src/compiler/ppc/instruction-selector-ppc.cc
diff --git a/src/compiler/ppc/instruction-selector-ppc.cc b/src/compiler/ppc/instruction-selector-ppc.cc
index 4d35516d51416cbe19368010eb966cf958835d06..8c503fad3689d3681f6a41142ca22a042b798dec 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -801,6 +801,8 @@ void InstructionSelector::VisitInt32PairAdd(Node* node) {
   Emit(kPPC_AddPair, 2, outputs, 4, inputs);
 }
 
+void InstructionSelector::VisitInt32PairSub(Node* node) { UNIMPLEMENTED(); }
+
 void VisitPairShift(InstructionSelector* selector, ArchOpcode opcode,
                     Node* node) {
   PPCOperandGenerator g(selector);