fix(opam): cleanly reject argumentless (and)/(or)

Otherwise they would raise a code error later.

Signed-off-by: Etienne Millon <me@emillon.org>

src/dune_rules/package.ml

@@ -168,10 +168,10 @@ module Dependency = struct
       fix (fun t ->
           let logops =
             [ ( "and"
-              , let+ x = repeat t in
+              , let+ x = repeat1 t in
                 And x )
             ; ( "or"
-              , let+ x = repeat t in
+              , let+ x = repeat1 t in
                 Or x )
             ]
           in

test/blackbox-tests/test-cases/opam-constraints.t

@@ -79,8 +79,12 @@ constraints.
   >   (p (and))))
   > EOF
 
-  $ dune build 2>&1 | grep 'Internal error'
-  Internal error, please report upstream including the contents of _build/log.
+  $ dune build
+  File "dune-project", line 6, characters 5-10:
+  6 |   (p (and))))
+           ^^^^^
+  Error: Not enough arguments for and
+  [1]
 
   $ cat > dune-project << EOF
   > (lang dune 2.1)
@@ -91,5 +95,9 @@ constraints.
   >   (p (or))))
   > EOF
 
-  $ dune build 2>&1 | grep 'Internal error'
-  Internal error, please report upstream including the contents of _build/log.
+  $ dune build
+  File "dune-project", line 6, characters 5-9:
+  6 |   (p (or))))
+           ^^^^
+  Error: Not enough arguments for or
+  [1]