Create a top-level "third_party" directory

This directory now contains third_party software that is vendored into
the Servo source tree. The idea is that it would eventually hold
webrender and other crates from mozilla-central as well with a standard
patch management approach for each.

third_party/WebIDL/tests/test_constructor_global.py

@@ -0,0 +1,72 @@
+import traceback
+
+
+def WebIDLTest(parser, harness):
+    threw = False
+    try:
+        parser.parse(
+            """
+            [Global, Exposed=TestConstructorGlobal]
+            interface TestConstructorGlobal {
+              constructor();
+            };
+        """
+        )
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset()
+    threw = False
+    try:
+        parser.parse(
+            """
+            [Global, Exposed=TestLegacyFactoryFunctionGlobal,
+             LegacyFactoryFunction=FooBar]
+            interface TestLegacyFactoryFunctionGlobal {
+            };
+        """
+        )
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset()
+    threw = False
+    try:
+        parser.parse(
+            """
+            [LegacyFactoryFunction=FooBar, Global,
+             Exposed=TestLegacyFactoryFunctionGlobal]
+            interface TestLegacyFactoryFunctionGlobal {
+            };
+        """
+        )
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")
+
+    parser = parser.reset()
+    threw = False
+    try:
+        parser.parse(
+            """
+            [Global, Exposed=TestHTMLConstructorGlobal]
+            interface TestHTMLConstructorGlobal {
+              [HTMLConstructor] constructor();
+            };
+        """
+        )
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should have thrown.")