Fix more MSVC warnings, this time mostly about possible value truncation (fixed

base/third_party/dmg_fp/g_fmt.cc

 /****************************************************************
  *
  * The author of this software is David M. Gay.
  *
  * Copyright (c) 1991, 1996 by Lucent Technologies.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose without fee is hereby granted, provided that this entire notice
  * is included in all copies of any software which is or includes a copy
  * or modification of this software and in all copies of the supporting
@@ skipping 49 matching lines @@
                 /* sprintf(b, "%+.2d", decpt - 1); */
                 if (--decpt < 0) {
                         *b++ = '-';
                         decpt = -decpt;
                         }
                 else
                         *b++ = '+';
                 for(j = 2, k = 10; 10*k <= decpt; j++, k *= 10) {}
                 for(;;) {
                         i = decpt / k;
-                        *b++ = i + '0';
+                        *b++ = (char)i + '0';
                         if (--j <= 0)
                                 break;
                         decpt -= i*k;
                         decpt *= 10;
                         }
                 *b = 0;
                 }
         else if (decpt <= 0) {
                 *b++ = '.';
                 for(; decpt < 0; decpt++)
@@ skipping 12 matching lines @@
                 }
  done0:
         freedtoa(s0);
 #ifdef IGNORE_ZERO_SIGN
  done:
 #endif
         return b0;
         }
 
 }  // namespace dmg_fp