Fix failing F# build and #1403

[A-Manning]

No description provided.

[mtzguido]

Thanks a lot for this! I made some changes to have a different error from non-linear patterns, and now the example in #1403 fails like this:

examples/bug-reports/bug1404.fst(9,6-10,17): (Error 297) Patterns in this match are incoherent, variable y is bound in some but not all patterns.

I'll merge this after running regression tests. Thanks again.

[nikswamy]

@A-Manning @mtzguido:

With @aseemr, we're looking at this change. It breaks the F# build for us on VS 2015.

Can you explain the rationale behind this change?

Thanks!
-Nik

[msprotz]

@tahina-pro had looked a long while ago into making F* build with VS2017 and VS2015 at the same time ... I seem to remember he got familiar with these assemblies details

[tahina-pro]

As far as I remember, changes I made on *.fsproj files in commit 4cc0e8b work in both VS2015 and VS2017.

Not sure what has changed since.

[A-Manning]

When trying to build with F# 4.1 using msbuild (also reproduced with rider 2017.3) I was getting errors resulting from FSharp.Core being resolved to 4.4.0.0, as in #1358.

I don't have VS, so I'm not able to test this in order to make it work with VS2015, VS2017, and F# 4.1. Perhaps these changes should be reverted.

[mtzguido]

Ouch, sorry to have merged this without checking the F# build... I'm trying to get my F# setup working again so I can test this. There's some more info in #1395.

[catalin-hritcu]

@nikswamy We are all migrating to VS2017, so can the reverted .fsproj file changes be reconsidered now?

[nikswamy]

yes

[nikswamy]

Note, I believe there was a related change to app.config by @aseemr that should probably also be reverted.

e0c4840#diff-2a0a2648fbce9a0e40f9bbda910c9d6b

[catalin-hritcu]

Okay, I'll try to reapply/re-revert these changes to my catalin_fsharp-4.1-upgrade branch and see if that helps with Windows CI. [Edit: it did!]