patch 8.1.0003: the :compiler command is not tested

Problem:    The :compiler command is not tested.
Solution:   Add a test. (Dominique Pelle, closes #2930)
diff --git a/src/testdir/test_alot.vim b/src/testdir/test_alot.vim
index b8a5650..ac3ca74 100644
--- a/src/testdir/test_alot.vim
+++ b/src/testdir/test_alot.vim
@@ -5,6 +5,7 @@
 source test_bufline.vim
 source test_cd.vim
 source test_changedtick.vim
+source test_compiler.vim
 source test_cursor_func.vim
 source test_delete.vim
 source test_ex_undo.vim