Name is bound multiple times is not reported in 'as' pattern

[auduchinok]

let f1 a a = ()
let f2 (a, b as c) c = ()
let f3 (a, b as c) a = ()

An error is expected in f3, but it's not reported:

[auduchinok]

What's interesting is name resolution also not being consistent here.

A more expected behaviour, the later a shadows the preceding one:

The preceding one is chosen instead:

[auduchinok]

It also reproduces when using an older FCS, so it's not related to the recent changes in #11674.