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 6106c514f14468f0a86c57a7abebbcc321578ea2..841a2048e0b836e332fad383229ce79ad4ae59ce 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -2354,6 +2354,13 @@ InstructionSelector::SupportedMachineOperatorFlags() {
          MachineOperatorBuilder::kWord64ReverseBits;
 }
 
+// static
+MachineOperatorBuilder::AlignmentRequirements
+InstructionSelector::AlignmentRequirements() {
+  return MachineOperatorBuilder::AlignmentRequirements::
+      FullUnalignedAccessSupport();
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8