dev-python/lit: Support running self-tests

dev-python/lit/lit-9999.ebuild

@@ -16,8 +16,18 @@ EGIT_REPO_URI="http://llvm.org/git/llvm.git
 LICENSE="UoI-NCSA"
 SLOT="0"
 KEYWORDS=""
-IUSE=""
+IUSE="test"
 
 S=${WORKDIR}/${P}/utils/lit
 
+# Tests require 'FileCheck' and 'not' utilities (from llvm)
+DEPEND="
+	test? (
+		dev-python/psutil[${PYTHON_USEDEP}]
+		sys-devel/llvm )"
+
 # TODO: move the manpage generation here (from sys-devel/llvm)
+
+python_test() {
+	./lit.py -sv tests || die
+}