Mark single-argument inline constructors as 'explicit'.

src/scopeinfo.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 202 matching lines @@
 
   struct Value {
     Value(Variable::Mode mode, int index) {
       ASSERT(ModeField::is_valid(mode));
       ASSERT(IndexField::is_valid(index));
       value_ = ModeField::encode(mode) | IndexField::encode(index);
       ASSERT(mode == this->mode());
       ASSERT(index == this->index());
     }
 
-    inline Value(uint32_t value) : value_(value) {}
+    explicit inline Value(uint32_t value) : value_(value) {}
 
     uint32_t raw() { return value_; }
 
     Variable::Mode mode() { return ModeField::decode(value_); }
 
     int index() { return IndexField::decode(value_); }
 
     // Bit fields in value_ (type, shift, size). Must be public so the
     // constants can be embedded in generated code.
     class ModeField:  public BitField<Variable::Mode, 0, 3> {};
     class IndexField: public BitField<int,            3, 32-3> {};
    private:
     uint32_t value_;
   };
 
   Key keys_[kLength];
   uint32_t values_[kLength];
 
   friend class Isolate;
   DISALLOW_COPY_AND_ASSIGN(ContextSlotCache);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCOPEINFO_H_