Fix a bunch of implicit casts detected by the Win64 compiler

samples/lineprocessor.cc

Index: samples/lineprocessor.cc
diff --git a/samples/lineprocessor.cc b/samples/lineprocessor.cc
index 7a84a2a0ffd2f29a785eafe36d071d9f7e9fcfd0..23e02142691dd1541b04c34d8fc2fb20717e069e 100644
--- a/samples/lineprocessor.cc
+++ b/samples/lineprocessor.cc
@@ -347,7 +347,7 @@ v8::Handle<v8::String> ReadFile(const char* name) {
   char* chars = new char[size + 1];
   chars[size] = '\0';
   for (int i = 0; i < size;) {
-    int read = fread(&chars[i], 1, size - i, file);
+    int read = static_cast<int>(fread(&chars[i], 1, size - i, file));
     i += read;
   }
   fclose(file);