[interpreter] A few code coverage improvements.

src/interpreter/constant-array-builder.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/interpreter/constant-array-builder.h"
 
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
@@ skipping 41 matching lines @@
 STATIC_CONST_MEMBER_DEFINITION const size_t
     ConstantArrayBuilder::k32BitCapacity;
 
 ConstantArrayBuilder::ConstantArrayBuilder(Isolate* isolate, Zone* zone)
     : isolate_(isolate), constants_map_(isolate->heap(), zone) {
   idx_slice_[0] =
       new (zone) ConstantArraySlice(zone, 0, k8BitCapacity, OperandSize::kByte);
   idx_slice_[1] = new (zone) ConstantArraySlice(
       zone, k8BitCapacity, k16BitCapacity, OperandSize::kShort);
   idx_slice_[2] = new (zone) ConstantArraySlice(
-      zone, k16BitCapacity, k32BitCapacity, OperandSize::kQuad);
+      zone, k8BitCapacity + k16BitCapacity, k32BitCapacity, OperandSize::kQuad);

[mythria, 2016/04/01 10:10:42]

This also fixes a clusterfuzz bug.
https://bugs.chromium.org/p/chromium/issues/detail?id=599000 :). 

 }
 
 size_t ConstantArrayBuilder::size() const {
   size_t i = arraysize(idx_slice_);
   while (i > 0) {
     ConstantArraySlice* slice = idx_slice_[--i];
     if (slice->size() > 0) {
       return slice->start_index() + slice->size();
     }
   }
@@ skipping 121 matching lines @@
   return index;
 }
 
 void ConstantArrayBuilder::DiscardReservedEntry(OperandSize operand_size) {
   OperandSizeToSlice(operand_size)->Unreserve();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8