Disable sourcekit’s tests on ubuntu-14.04

swiftlang#8485 (comment)

test/SourceKit/lit.local.cfg

@@ -1,6 +1,9 @@
 if 'sourcekit' not in config.available_features:
     config.unsupported = True
 
+elif 'OS=linux-gnu' in config.available_features and 'LinuxDistribution=Ubuntu-14.04' in config.available_features:
+    config.unsupported = True
+
 else:
     config.sourcekitd_test = config.inferSwiftBinary('sourcekitd-test')
     config.complete_test = config.inferSwiftBinary('complete-test')

test/lit.cfg

@@ -1085,4 +1085,20 @@ if config.lldb_build_root != "":
     python_lib_dir = get_python_lib(True, False, config.lldb_build_root)
     config.substitutions.append(('%lldb-python-path', python_lib_dir))
 
+
+# Run lsb_release on the target to be tested and return the results.
+def linux_get_lsb_release():
+    lsb_release_path = '/usr/bin/lsb_release'
+    if os.path.isfile(lsb_release_path) and os.access(lsb_release_path, os.X_OK):
+        distributor = lit.util.executeCommand([lsb_release_path, '-is'])[0].rstrip()
+        release = lit.util.executeCommand([lsb_release_path, '-rs'])[0].rstrip()
+        return (distributor, release)
+    return ('', '')
+
+if platform.system() == 'Linux':
+    (distributor, release) = linux_get_lsb_release()
+    if distributor != '' and release != '':
+        config.available_features.add("LinuxDistribution=" + distributor + '-' + release)
+        lit_config.note('Running tests on %s-%s' % (distributor, release))
+
 lit_config.note("Available features: " + ", ".join(config.available_features))