The expected ordering for this keyword in parameter list has been relaxed according to these LDM notes, so in this int and this in int both parse.
But scoped in this int doesn't parse, while this scoped in int parses.

The logic is in ParseParameterModifiers and it doesn't look for this after it found a "scoped" that is recognized as a keyword.

Reported by @tannergooding in #78491 (comment)
Tagging @cston to confirm expectations