Fix compareCustom function in IrLineNumberTest class, to exclude comment

[neetopia]

Fix compareCustom function in IrLineNumberTest class, to exclude comment lines that are not related to line number verification.

Unmute a test case should have been unmuted but shadowed by this bug.

[madsager]

How about simplifying this to:

    val expectedLineNumbers = normalize(
        fileText.substring(Regex("// \\d+").find(fileText)!!.range.start + 2)
            .trim().split(" ").map { it.trim() }.toMutableList()
    )

Then we are looking for a line that starts with "// " with a number of digits after it. That should work to exclude the comment lines with text. That looks consistent with what the old backend expects from these tests.

[neetopia]

Looks reasonable since this is how old test is doing. I was a little bit overthinking this, was considering the case where there is a trailing comment line after line numbers

[neetopia]

I am also considering adding an optional "+" check before digit check, since there are line numbers start with a "+", although such case is not present in current test data yet.

[max-kammerer]

It wouldn't presented in future (answered in slack)

[max-kammerer]

Thanks!