Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/wasm/ast-decoder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/signature.h"
 
 #include "src/bit-vector.h"
 #include "src/flags.h"
 #include "src/handles.h"
 #include "src/zone-containers.h"
@@ skipping 1298 matching lines @@
                                              p->tree->node, expr->node);
       }
     }
   }
 
   void ReduceLoadMem(Production* p, LocalType type, MachineType mem_type) {
     DCHECK_EQ(1, p->index);
     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);
     }
   }
 
   void ReduceStoreMem(Production* p, LocalType type, MachineType mem_type) {
     if (p->index == 1) {
       TypeCheckLast(p, kAstI32);  // index
     } else {
       DCHECK_EQ(2, p->index);
       TypeCheckLast(p, type);
       if (build()) {
         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;
       }
     }
   }
 
   void TypeCheckLast(Production* p, LocalType expected) {
     LocalType result = p->last()->type;
     if (result == expected) return;
     if (result == kAstEnd) return;
     if (expected != kAstStmt) {
@@ skipping 438 matching lines @@
 BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, size_t num_locals,
                                            const byte* start, const byte* end) {
   FunctionBody body = {nullptr, nullptr, nullptr, start, end};
   SR_WasmDecoder decoder(zone, nullptr, body);
   return decoder.AnalyzeLoopAssignmentForTesting(start, num_locals);
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8