Implement UnaligedLoad and UnaligedStore turbofan operators.

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 8fbd69c0ee57a7d587db4d4c3de128d0a948bd74..2e8f6254a0667224d503a2f00b493ed6b09c9350 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -327,6 +327,11 @@ void InstructionSelector::VisitStore(Node* node) {
   }
 }
 
+// Architecture supports unaligned access, therefore VisitLoad is used instead
+void InstructionSelector::VisitUnalignedLoad(Node* node) { UNREACHABLE(); }
+
+// Architecture supports unaligned access, therefore VisitStore is used instead
+void InstructionSelector::VisitUnalignedStore(Node* node) { UNREACHABLE(); }
 
 void InstructionSelector::VisitCheckedLoad(Node* node) {
   CheckedLoadRepresentation load_rep = CheckedLoadRepresentationOf(node->op());