Set IGC_DEBUG with --enable-checking=igc_debug

configure.ac

@@ -699,7 +699,7 @@ AC_ARG_ENABLE([checking],
 		 enable only specific categories of checks.
 		 Categories are: all,yes,no.
 		 Flags are: stringbytes, stringoverrun, stringfreelist,
-		 igc_check_fwd,
+		 igc_check_fwd, igc_debug,
 		 structs, glyphs])],
 [ac_checking_flags="${enableval}"],[])
 IFS="${IFS= 	}"; ac_save_IFS="$IFS"; IFS="$IFS,"
@@ -729,6 +729,7 @@ do
 	glyphs)		ac_glyphs_debug=1 ;;
 	# Very special case, so don't include it in all.
 	igc_check_fwd)	ac_igc_check_fwd=1 ;;
+	igc_debug)	ac_igc_debug=1 ;;
 	*)	AC_MSG_ERROR([uuu unknown check category $check]) ;;
 	esac
 done
@@ -780,6 +781,10 @@ AS_IF([test "$with_android" = no || test -n "$XCONFIGURE"],[
     AC_DEFINE([IGC_CHECK_FWD], [1],
   [Define this to enable igc forwarding check code.])
   fi
+  if test x$ac_igc_debug != x ; then
+    AC_DEFINE([IGC_DEBUG], [1],
+  [Define this to enable igc assertions.])
+  fi
 ],[AS_IF([test "x$ac_enable_checking" != x],
     [android_enable_checking=yes
      export android_enable_checking])])

src/igc.h

@@ -61,9 +61,6 @@ enum igc_obj_type
 
 #ifdef HAVE_MPS
 
-/* Assertions.  */
-# define IGC_DEBUG 1
-
 void igc_break (void);
 void init_igc (void);
 void syms_of_igc (void);