Wrong actual type is captured in diagnostic

[auduchinok]

In the code below the expected type is int and the actual is string:

module Module

type T() =
    static member P1 = T.P2 + 1
    static member P2 = ""

However, the diagnostic data captures the opposite:

This seems to be a regression in #18851. cc @DedSec256

[DedSec256]

It's a hornet's nest.

Based on the error message, we can assume that the type string was expected, but int arrived. For P2, the type string is also inferred instead of int

At the same time, if we swap the arguments of the +, we get the expected int and the actual string.

Unfortunately, most of the logic does not divide the types into expected and actual, it only reports a mismatch, and then the error messages interpret the types in some order.

I have a few questions.:

• Should this error really be reported in this place?
• What is really considered to be the expected and actual type in this case? Is the error message itself correct?

Also, this issue is not a regression #18851 since before it, both expected and actual types would have been string.