Testing: some tests kill the testhost from the inside

[majocha]

StringInterpolation - interpolated strings executes exit 1 in a fsi session, killing the test run:

fsharp/tests/FSharp.Compiler.ComponentTests/InteractiveSession/Misc.fs

Lines 1994 to 2009 in 6609928

	[<Fact>]
	let ``StringInterpolation - interpolated strings``() =
	Fsx """
	let name = "World"
	let count = 42
	let greeting = $"Hello, {name}! Count: {count}"
	if greeting <> "Hello, World! Count: 42" then exit 1
	let formatted = $"Pi is approximately {System.Math.PI:F2}"
	if not (formatted.Contains("3.14")) then exit 1
	()
	"""
	|> withOptions ["--nologo"]
	|> runFsi
	|> shouldSucceed
	|> ignore

A safeguard could be to preemptively shadow exit when creating a fsi session:

script.Eval("let exit _ = ...")

The test fails locally because of system language settings. Apparently, I had CurrentUICulture En-US but CurrentCulture pl-PL. The latter decides about formatting.