[ARC] Define SIZE_TYPE and PTRDIFF_TYPE correctly.

This silences tons of -Wformat= warnings when building ARC Linux kernel
with gcc 6.x (and restores the ARC gcc 4.8.x behaviour) which had
similar fix.

gcc/
2016-11-03  Vineet Gupta  <vgupta@synopsys.com>

	* config/arc/arc.h (SIZE_TYPE): Define as unsigned int.
	(PTRDIFF_TYPE): Define as int.

From-SVN: r241812

gcc/ChangeLog

+2016-11-03  Vineet Gupta  <vgupta@synopsys.com>
+
+	* config/arc/arc.h (SIZE_TYPE): Define as unsigned int.
+	(PTRDIFF_TYPE): Define as int.
+
 2016-11-03  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>
 
 	* ccmp.c (expand_ccmp_expr_1): Adjust.

gcc/config/arc/arc.h

@@ -409,8 +409,8 @@ if (GET_MODE_CLASS (MODE) == MODE_INT		\
 /* Define this as 1 if `char' should by default be signed; else as 0.  */
 #define DEFAULT_SIGNED_CHAR 0
 
-#define SIZE_TYPE "long unsigned int"
-#define PTRDIFF_TYPE "long int"
+#define SIZE_TYPE "unsigned int"
+#define PTRDIFF_TYPE "int"
 #define WCHAR_TYPE "int"
 #define WCHAR_TYPE_SIZE 32