[llvm] [CI] Test lit when it is changed (PR #159359)

[Aiden Grossman via llvm-commits]

================
@@ -413,6 +413,30 @@ def test_third_party_benchmark(self):
             "check-cxx check-cxxabi check-unwind",
         )
 
+    def test_lit(self):
+        env_variables = compute_projects.get_env_variables(
+            ["llvm/utils/lit/CMakeLists.txt"], "Linux"
+        )
+        self.assertEqual(
+            env_variables["projects_to_build"],
+            "bolt;clang;clang-tools-extra;flang;lld;lldb;llvm;mlir;polly",
+        )
+        self.assertEqual(
+            env_variables["project_check_targets"],
+            "check-bolt check-clang check-clang-tools check-flang check-lit check-lld check-lldb check-llvm check-mlir check-polly",
----------------
boomanaiden154 wrote:

Given touching lit (`llvm/utils/lit`) also touches llvm, we end up testing everything that touching LLVM would. I think this is reasonable enough behavior given it serves as integration testing for lit.

https://github.com/llvm/llvm-project/pull/159359