[wasm][asm2wasm] Fixes a bug in 8-bit heap view accesses.

src/asmjs/asm-typer.cc

 // Copyright 2016 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/asmjs/asm-typer.h"
 
 #include <algorithm>
 #include <limits>
 #include <memory>
 #include <string>
@@ skipping 2444 matching lines @@
         ExtractHeapAccessShift(key_as_binop->right(), &shift) &&
         (1 << shift) == obj_type->ElementSizeInBytes()) {
       AsmType* type;
       RECURSE(type = ValidateExpression(key_as_binop->left()));
       if (type->IsA(AsmType::Intish())) {
         if (access_type == LoadFromHeap) {
           return obj_type->LoadType();
         }
         return obj_type->StoreType();
       }
-      // TODO(jpp): it may be the case that, if type is not an Intish, we could
-      // fail here instead of letting the validator try using the "leniency"
-      // rule (i.e., allow unshifted indexes for heap views of 8-bit integers.
+      FAIL(key_as_binop, "Invalid heap access index.");
     }
   }
 
   if (obj_type->ElementSizeInBytes() == 1) {
     // Leniency: if this is a byte array, we don't require the shift operation
     // to be present.
     AsmType* index_type;
     RECURSE(index_type = ValidateExpression(heap->key()));
     if (!index_type->IsA(AsmType::Int())) {
       FAIL(heap, "Invalid heap access index for byte array.");
@@ skipping 261 matching lines @@
     return true;
   }
 
   *error_message = typer.error_message();
   return false;
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8