Implement UnalignedLoad and UnalignedStore in WASM using LoadByte/Shift/Or and StoreByte/Shift/And.

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 240a4f2b205ae9aac90527e9a92e59263502964d..03e19cf0542279e8aa02b20b5fa53c17adf10df6 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -2417,6 +2417,13 @@ InstructionSelector::SupportedMachineOperatorFlags() {
          MachineOperatorBuilder::kWord64ReverseBits;
 }
 
+// static
+MachineOperatorBuilder::AlignmentRequirements
+InstructionSelector::AlignmentRequirements() {
+  return MachineOperatorBuilder::AlignmentRequirements::
+      FullUnalignedAccessSupport();
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8