Add test case for duplicate c_names/cxx_names

The current error message should be improved

Signed-off-by: Rudi Grinberg <rudi.grinberg@gmail.com>

test/blackbox-tests/dune.inc

@@ -207,6 +207,14 @@
    test-cases/dup-fields
    (progn (run %{exe:cram.exe} -test run.t) (diff? run.t run.t.corrected)))))
 
+(alias
+ (name duplicate-c-cxx)
+ (deps (package dune) (source_tree test-cases/duplicate-c-cxx))
+ (action
+  (chdir
+   test-cases/duplicate-c-cxx
+   (progn (run %{exe:cram.exe} -test run.t) (diff? run.t run.t.corrected)))))
+
 (alias
  (name duplicate-target-no-loc)
  (deps (package dune) (source_tree test-cases/duplicate-target-no-loc))
@@ -1261,6 +1269,7 @@
   (alias dune-ppx-driver-system)
   (alias dune-project-edition)
   (alias dup-fields)
+  (alias duplicate-c-cxx)
   (alias duplicate-target-no-loc)
   (alias embed-jbuild)
   (alias enabled_if)
@@ -1414,6 +1423,7 @@
   (alias dune-ppx-driver-system)
   (alias dune-project-edition)
   (alias dup-fields)
+  (alias duplicate-c-cxx)
   (alias duplicate-target-no-loc)
   (alias embed-jbuild)
   (alias enabled_if)

test/blackbox-tests/test-cases/duplicate-c-cxx/dune

@@ -0,0 +1,4 @@
+(library
+ (name foo)
+ (c_names foo)
+ (cxx_names foo))

test/blackbox-tests/test-cases/duplicate-c-cxx/run.t

@@ -0,0 +1,9 @@
+c_names and cxx_names with overlapping names
+  $ dune build @all
+  Info: creating file dune-project with this contents:
+  | (lang dune 1.7)
+
+  Multiple rules generated for _build/default/foo$ext_obj:
+  - dune:3
+  - dune:4
+  [1]

test/blackbox-tests/test-cases/menhir/run.t

@@ -75,8 +75,8 @@ Reproduction case for #1781, only the .ml and .mli should be promoted:
   $ dune build @all --root promote
   Entering directory 'promote'
   $ ls -1 promote/_build/default | grep mock
-  parser__mock.mli.inferred
   parser__mock.ml.mock
+  parser__mock.mli.inferred
   $ ls -1 promote | grep mock
   [1]
 Check what is being generated exactly: