[fusl] Add llvm's lit tool to third_party

third_party/lit/tests/Inputs/test-data/lit.cfg

+import os
+try:
+    import ConfigParser
+except ImportError:
+    import configparser as ConfigParser
+
+import lit.formats
+import lit.Test
+
+class DummyFormat(lit.formats.FileBasedTest):
+    def execute(self, test, lit_config):
+        # In this dummy format, expect that each test file is actually just a
+        # .ini format dump of the results to report.
+
+        source_path = test.getSourcePath()
+
+        cfg = ConfigParser.ConfigParser()
+        cfg.read(source_path)
+
+        # Create the basic test result.
+        result_code = cfg.get('global', 'result_code')
+        result_output = cfg.get('global', 'result_output')
+        result = lit.Test.Result(getattr(lit.Test, result_code),
+                                 result_output)
+
+        # Load additional metrics.
+        for key,value_str in cfg.items('results'):
+            value = eval(value_str)
+            if isinstance(value, int):
+                metric = lit.Test.IntMetricValue(value)
+            elif isinstance(value, float):
+                metric = lit.Test.RealMetricValue(value)
+            else:
+                raise RuntimeError("unsupported result type")
+            result.addMetric(key, metric)
+
+        return result
+
+config.name = 'test-data'
+config.suffixes = ['.ini']
+config.test_format = DummyFormat()
+config.test_source_root = None
+config.test_exec_root = None
+config.target_triple = None