Ignore InterfaceConsts changes in v7.1..v8.0

Context: #5 (comment)

Before API-26, `Java.Lang.Reflect.Constructor` and
`Java.Lang.Reflect.Method` had nested `InterfaceConsts` types.
In API-26, `Constructor` and `Method` were updated with a different,
*common*, base class: `Java.Lang.Reflect.Executable`.

`Executable` got the `InterfaceConsts` nested type, and `Constructor`
and `Method` "lost" them, because it was "moved" to the base class.

This is fine API-wise (`Constructor.InterfaceConsts` is still
something the C# compiler will accept) and ABI-wise (`InterfaceConsts`
only contained `const` members, so -- unless using reflection -- it's
not possible for IL to contain a member reference within that type).

However, `mono-api-html` doesn't know that.

Add a `inter-api-extra-v7.1-v8.0.txt` file to pass the following
additional arguments to `mono-api-html`:

	-r 'Java.Lang.Reflect.Constructor.InterfaceConsts'
	-r 'Java.Lang.Reflect.Method.InterfaceConsts'

This prevents `mono-api-html` from erroring on those changes.

Author: jonpryor

inter-api-extra-v7.1-v8.0.txt

@@ -0,0 +1,2 @@
+-r 'Java.Lang.Reflect.Constructor.InterfaceConsts'
+-r 'Java.Lang.Reflect.Method.InterfaceConsts'