CLI args: add pactest with an invalid combination

Pacman should catch cases in which the passed arguments don't apply to the
current operation (sync/query/...).

Also see FS#20950.

Signed-off-by: Dan McGee <dan@archlinux.org>

test/pacman/tests/pacman005.py

@@ -0,0 +1,11 @@
+self.description = "Test invalid combination of command line options (-Qy)"
+
+p = pmpkg("foobar")
+self.addpkg2db("local", p)
+
+self.args = "-Qy"
+
+self.addrule("PACMAN_RETCODE=1")
+
+self.expectfailure = True
+