Hover on named constructor invocation length is incorrect

[FMorschel]

Somewhat related to #28537 and #62000.

Repro:

/// Docs on the class
class MyClass {
  /// Docs on the other constructor
  MyClass.other();
}

void foo(MyClass c) {
  foo(MyClass.other());
}

We should be able to hover over either MyClass or other to see the different docs.

@DanTup, would you like to take a look at this one, too? Since you've fixed that other one too.

FYI @bwilkerson