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

samples/process.cc

 // Copyright 2012 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 577 matching lines @@
   }
 }
 
 
 // Reads a file into a v8 string.
 Handle<String> ReadFile(Isolate* isolate, const string& name) {
   FILE* file = fopen(name.c_str(), "rb");
   if (file == NULL) return Handle<String>();
 
   fseek(file, 0, SEEK_END);
-  int size = ftell(file);
+  size_t size = ftell(file);
   rewind(file);
 
   char* chars = new char[size + 1];
   chars[size] = '\0';
-  for (int i = 0; i < size;) {
-    int read = static_cast<int>(fread(&chars[i], 1, size - i, file));
-    i += read;
+  for (size_t i = 0; i < size;) {
+    i += fread(&chars[i], 1, size - i, file);
+    if (ferror(file)) {
+      fclose(file);
+      return Handle<String>();
+    }
   }
   fclose(file);
-  Handle<String> result =
-      String::NewFromUtf8(isolate, chars, String::kNormalString, size);
+  Handle<String> result = String::NewFromUtf8(
+      isolate, chars, String::kNormalString, static_cast<int>(size));
   delete[] chars;
   return result;
 }
 
 
 const int kSampleSize = 6;
 StringHttpRequest kSampleRequests[kSampleSize] = {
   StringHttpRequest("/process.cc", "localhost", "google.com", "firefox"),
   StringHttpRequest("/", "localhost", "google.net", "firefox"),
   StringHttpRequest("/", "localhost", "google.org", "safari"),
@@ skipping 44 matching lines @@
   JsHttpRequestProcessor processor(isolate, source);
   map<string, string> output;
   if (!processor.Initialize(&options, &output)) {
     fprintf(stderr, "Error initializing processor.\n");
     return 1;
   }
   if (!ProcessEntries(&processor, kSampleSize, kSampleRequests))
     return 1;
   PrintMap(&output);
 }