declaredlocs followup: handle cannot instantiate errors

[timotheecour]

follows #15666 and #15673

IIRC that was the last remaining case

when true:
  type Foo[T: SomeInteger] = object
  var a: Foo[float]

before PR:

t12178.nim(8, 13) Error: cannot instantiate Foo
got: <typedesc[float]>
but expected: <T: SomeInteger>
    var a: Foo[float]

after PR:

t12178.nim(8, 13) Error: cannot instantiate Foo [type declared in t12178.nim(7, 8)]
got: <typedesc[float]>
but expected: <T: SomeInteger>
    var a: Foo[float]