[wasm] Add ProtectedStore instruction

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 26dae650256a2ae3e5e0032a027ba5ac0c2e6ec0..c96c891fa9a437e9824081f4a89e25e66dacd5ec 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -339,6 +339,11 @@ void InstructionSelector::VisitStore(Node* node) {
   }
 }
 
+void InstructionSelector::VisitProtectedStore(Node* node) {
+  // TODO(eholk)
+  UNIMPLEMENTED();
+}
+
 // Architecture supports unaligned access, therefore VisitLoad is used instead
 void InstructionSelector::VisitUnalignedLoad(Node* node) { UNREACHABLE(); }