Implement [Inline] interfaces

Inline interfaces just appear as a Rust type and in the TypeId hierarchy.
They are completely invisible on the JS side.

components/script/dom/bindings/codegen/parser/inline.patch

@@ -0,0 +1,12 @@
+--- WebIDL.py
++++ WebIDL.py
+@@ -1695,7 +1695,8 @@ class IDLInterface(IDLInterfaceOrNamespace):
+                   identifier == "ProbablyShortLivingObject" or
+                   identifier == "LegacyUnenumerableNamedProperties" or
+                   identifier == "NonOrdinaryGetPrototypeOf" or
+-                  identifier == "Abstract"):
++                  identifier == "Abstract" or
++                  identifier == "Inline"):
+                 # Known extended attributes that do not take values
+                 if not attr.noArguments():
+                     raise WebIDLError("[%s] must take no arguments" % identifier,