Enable tests on FreeBSD. A fair amount of them passes already.

Author: dcci

test/lit.cfg

@@ -607,13 +607,16 @@ if run_vendor == 'apple':
         "%s ld -L%s" %
         (xcrun_prefix, os.path.join(test_resource_dir, config.target_sdk_name)))
 
-elif run_os == 'linux-gnu' or run_os == 'linux-gnueabihf':
-    # Linux
-    lit_config.note("Testing Linux " + config.variant_triple)
+elif run_os == 'linux-gnu' or run_os == 'linux-gnueabihf' or run_os == 'freebsd':
+    # Linux/FreeBSD
+    if run_os == 'freebsd':
+      lit_config.note("Testing FreeBSD " + config.variant_triple)
+    else:
+      lit_config.note("Testing Linux " + config.variant_triple)
     config.target_object_format = "elf"
     config.target_runtime = "native"
     config.target_swift_autolink_extract = inferSwiftBinary("swift-autolink-extract")
-    config.target_sdk_name = "linux"
+    config.target_sdk_name = "freebsd" if run_os == "freebsd" else "linux"
     config.target_build_swift = (
         '%s -target %s %s %s %s %s'
         % (config.swiftc, config.variant_triple, resource_dir_opt, mcp_opt,