Remove incorrect casts to 'unsigned' that lose info on 64-bit hosts.

These casts should not be needed on 32-bit hosts, either.
* keyboard.c (read_char):
* lread.c (Fload): Remove casts to unsigned.

src/ChangeLog

 2011-06-12  Paul Eggert  <eggert@cs.ucla.edu>
 
+	Remove incorrect casts to 'unsigned' that lose info on 64-bit hosts.
+	These casts should not be needed on 32-bit hosts, either.
+	* keyboard.c (read_char):
+	* lread.c (Fload): Remove casts to unsigned.
+
 	* lisp.h (UNSIGNED_CMP): New macro.
 	This fixes comparison bugs on 64-bit hosts.
 	(ASCII_CHAR_P): Use it.

src/keyboard.c

@@ -2959,9 +2959,7 @@ read_char (int commandflag, int nmaps, Lisp_Object *maps, Lisp_Object prev_event
      save the echo area contents for it to refer to.  */
   if (INTEGERP (c)
       && ! NILP (Vinput_method_function)
-      && (unsigned) XINT (c) >= ' '
-      && (unsigned) XINT (c) != 127
-      && (unsigned) XINT (c) < 256)
+      && ' ' <= XINT (c) && XINT (c) < 256 && XINT (c) != 127)
     {
       previous_echo_area_message = Fcurrent_message ();
       Vinput_method_previous_message = previous_echo_area_message;
@@ -2986,9 +2984,7 @@ read_char (int commandflag, int nmaps, Lisp_Object *maps, Lisp_Object prev_event
       /* Don't run the input method within a key sequence,
 	 after the first event of the key sequence.  */
       && NILP (prev_event)
-      && (unsigned) XINT (c) >= ' '
-      && (unsigned) XINT (c) != 127
-      && (unsigned) XINT (c) < 256)
+      && ' ' <= XINT (c) && XINT (c) < 256 && XINT (c) != 127)
     {
       Lisp_Object keys;
       int key_count, key_count_reset;

src/lread.c

@@ -1208,7 +1208,7 @@ Return t if the file exists and loads successfully.  */)
 	  result = stat (SSDATA (efound), &s2);
 	  SSET (efound, SBYTES (efound) - 1, 'c');
 
-	  if (result >= 0 && (unsigned) s1.st_mtime < (unsigned) s2.st_mtime)
+	  if (result == 0 && s1.st_mtime < s2.st_mtime)
 	    {
 	      /* Make the progress messages mention that source is newer.  */
 	      newer = 1;