diff: report errors for duplicate mode declarations

[Fergus Henderson]

I wrote:

>Report an error for duplicate mode declarations.

A bit of testing revealed I need to make a couple more changes.

--------------------

tests/valid/qualified_cons_id.m:
library/int.m:
	Fix duplicate mode declaration errors.

cvs diff  library/int.m tests/valid/qualified_cons_id.m
Index: library/int.m
===================================================================
RCS file: /home/mercury1/repository/mercury/library/int.m,v
retrieving revision 1.47
diff -u -r1.47 int.m
--- int.m	1997/11/21 06:49:23	1.47
+++ int.m	1997/11/23 04:36:55
@@ -163,7 +163,6 @@
 
 :- pred builtin_plus(int, int, int).
 :- mode builtin_plus(in, in, uo) is det.
-:- mode builtin_plus(in, in, uo) is det.
 
 :- pred builtin_unary_plus(int, int).
 :- mode builtin_unary_plus(in, uo) is det.
Index: tests/valid/qualified_cons_id.m
===================================================================
RCS file: /home/mercury1/repository/tests/valid/qualified_cons_id.m,v
retrieving revision 1.2
diff -u -r1.2 qualified_cons_id.m
--- qualified_cons_id.m	1997/02/17 01:41:48	1.2
+++ qualified_cons_id.m	1997/11/23 05:12:40
@@ -13,8 +13,13 @@
 
 :- pred test(maybe(T), T).
 :- mode test(in(bound(std_util:yes(ground))), out) is det.
-:- mode test(in(yes), out) is det.
+
+:- pred test2(maybe(T), T).
+:- mode test2(in(yes), out) is det.
 
 :- implementation.
 
 test(std_util:yes(T), T).
+
+test2(std_util:yes(T), T).
+