Smal fixes for https://github.com/Microsoft/visualfsharp/pull/5940

[AviAvni]

Small fixes according to @blumu review

[cartermp]

Issues:

2018-11-20T21:52:20.8974046Z Errors and Failures
2018-11-20T21:52:20.8974076Z 
2018-11-20T21:52:20.8974124Z 1) Failed : Tests.Service.Editor.Printf specifiers for triple-quote strings
2018-11-20T21:52:20.8974180Z   Expected: [|(2, 19, 2, 22, 1); (4, 12, 4, 15, 1); (6, 29, 6, 32, 1); (7, 29, 7, 31, 1);
2018-11-20T21:52:20.8974342Z   (7, 33, 7, 35, 1)|]
2018-11-20T21:52:20.8974396Z Actual: [|(2, 19, 2, 22, 1); (4, 12, 4, 15, 1); (6, 27, 6, 30, 1); (7, 29, 7, 31, 1);
2018-11-20T21:52:20.8974444Z   (7, 33, 7, 35, 1)|]
2018-11-20T21:52:20.8974533Z   Expected and actual are both <System.Tuple`5[System.Int32,System.Int32,System.Int32,System.Int32,System.Int32][5]>
2018-11-20T21:52:20.8974586Z   Values differ at index [2]
2018-11-20T21:52:20.8974633Z   Expected: <(6, 29, 6, 32, 1)>
2018-11-20T21:52:20.8974718Z   But was:  <(6, 27, 6, 30, 1)>
2018-11-20T21:52:20.8974766Z at FsUnit.shouldEqual[a](a x, a y)
2018-11-20T21:52:20.8974818Z at Tests.Service.Editor.Printf specifiers for triple-quote strings()

Looks like the same failing test in other CI runs.

[cartermp]

Thanks @AviAvni

[cartermp]

@dsyme the code for this doesn't appear to have a test for correctness. Any ideas on adding a regression test for this?

[dsyme]

IIRC this code was added to FCS and there were normally tests added for everything we did there. So the FCS tests would be the right place