i386: Define __ILP32__ and _ILP32 for all 32-bit targets

	* config/i386/i386-c.c (ix86_target_macros): Define _ILP32 and
	__ILP32__ for 32-bit targets.

gcc/ChangeLog

+2020-05-19  Gerald Pfeifer  <gerald@pfeifer.com>
+
+	Backport from mainline
+	2020-05-10  Gerald Pfeifer  <gerald@pfeifer.com>
+
+	* config/i386/i386-c.c (ix86_target_macros): Define _ILP32 and
+	__ILP32__ for 32-bit targets.
+
 2020-05-19  Tobias Burnus  <tobias@codesourcery.com>
 
 	Backport from mainline

gcc/config/i386/i386-c.c

@@ -697,6 +697,8 @@ ix86_target_macros (void)
       cpp_assert (parse_in, "cpu=i386");
       cpp_assert (parse_in, "machine=i386");
       builtin_define_std ("i386");
+      cpp_define (parse_in, "_ILP32");
+      cpp_define (parse_in, "__ILP32__");
     }
 
   if (!TARGET_80387)