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

src/compiler/ia32/instruction-selector-ia32.cc

Index: src/compiler/ia32/instruction-selector-ia32.cc
diff --git a/src/compiler/ia32/instruction-selector-ia32.cc b/src/compiler/ia32/instruction-selector-ia32.cc
index 120e98cb5dce886788907d4b58b06bc9095fefeb..d2f58d73275a99681cc4ae0229671456b5799668 100644
--- a/src/compiler/ia32/instruction-selector-ia32.cc
+++ b/src/compiler/ia32/instruction-selector-ia32.cc
@@ -1691,6 +1691,13 @@ InstructionSelector::SupportedMachineOperatorFlags() {
   return flags;
 }
 
+// static
+MachineOperatorBuilder::AlignmentRequirements
+InstructionSelector::AlignmentRequirements() {
+  return MachineOperatorBuilder::AlignmentRequirements::
+      FullUnalignedAccessSupport();
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8