[clang] Use -Wshorten-64-to-32 to enable warnings about 64bit to 32bit truncations.

src/flags.cc

 // Copyright 2006-2008 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 <cctype>
 #include <cstdlib>
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 376 matching lines @@
       // set the flag
       char* endp = const_cast<char*>("");  // *endp is only read
       switch (flag->type()) {
         case Flag::TYPE_BOOL:
           *flag->bool_variable() = !is_bool;
           break;
         case Flag::TYPE_MAYBE_BOOL:
           *flag->maybe_bool_variable() = MaybeBoolFlag::Create(true, !is_bool);
           break;
         case Flag::TYPE_INT:
-          *flag->int_variable() = strtol(value, &endp, 10);  // NOLINT
+          *flag->int_variable() = static_cast<int>(strtol(value, &endp, 10));
           break;
         case Flag::TYPE_FLOAT:
           *flag->float_variable() = strtod(value, &endp);
           break;
         case Flag::TYPE_STRING:
           flag->set_string_value(value ? StrDup(value) : NULL, true);
           break;
         case Flag::TYPE_ARGS: {
           int start_pos = (value == NULL) ? i : i - 1;
           int js_argc = *argc - start_pos;
@@ skipping 160 matching lines @@
 void FlagList::EnforceFlagImplications() {
 #define FLAG_MODE_DEFINE_IMPLICATIONS
 #include "src/flag-definitions.h"
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
   ComputeFlagListHash();
 }
 
 
 uint32_t FlagList::Hash() { return flag_hash; }
 } }  // namespace v8::internal