Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index 0f6128da9da739abb92b6af279d43ed2586b0f16..d4c21d64cb1ab8d20f47733c61db702ef0ee8747 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -485,6 +485,11 @@ 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());