Fix tests

[DedSec256]

It seems that in

fsharp/src/fsharp/symbols/SymbolHelpers.fs

Line 196 in 12c8309

if allErrors || fileName = mainInputFileName || fileName = TcGlobals.DummyFileNameForRangesWithoutASpecificLocation then

check fileName = mainInputFileName is not passing
since one of them has the form /home/user/Test.fsx and the other one is normalized to the form C:/home/user/Test.fsx

due to which some diagnostics may not be reported (like here #12865 (comment))

[auduchinok]

@vzarytovskii We weren't able to find out why it hadn't been failing before, but for some reason it started failing even locally in main, so I assume it'll fix the failures in #12865.

[vzarytovskii]

@vzarytovskii We weren't able to find out why it hadn't been failing before, but for some reason it started failing even locally in main, so I assume it'll fix the failures in #12865.

Thanks for fixing it. It is indeed weird why it wasn't failing before. I will find some time to dig into it.