Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/wasm/ast-decoder.cc

Index: src/wasm/ast-decoder.cc
diff --git a/src/wasm/ast-decoder.cc b/src/wasm/ast-decoder.cc
index 0d0c6e0fb0f3e83433895e408b02ee0a376cc938..be306097bbc54864bad4cb781014845b340d65a5 100644
--- a/src/wasm/ast-decoder.cc
+++ b/src/wasm/ast-decoder.cc
@@ -1323,8 +1323,8 @@ class SR_WasmDecoder : public WasmDecoder {
     TypeCheckLast(p, kAstI32);  // index
     if (build()) {
       MemoryAccessOperand operand(this, p->pc());
-      p->tree->node =
-          builder_->LoadMem(type, mem_type, p->last()->node, operand.offset);
+      p->tree->node = builder_->LoadMem(type, mem_type, p->last()->node,
+                                        operand.offset, operand.alignment);
     }
   }
 
@@ -1338,7 +1338,7 @@ class SR_WasmDecoder : public WasmDecoder {
         MemoryAccessOperand operand(this, p->pc());
         TFNode* val = p->tree->children[1]->node;
         builder_->StoreMem(mem_type, p->tree->children[0]->node, operand.offset,
-                           val);
+                           operand.alignment, val);
         p->tree->node = val;
       }
     }