Fix code that assumes suites are under a vcs repository

[zakkak]

As of mx 5.270.0 (graalvm/mx#221), mx projects can be built even outside a vcs repository.
This patch makes the necessary changes to allow graal to be built outside a vcs repository.

[dougxc]

Is there some way we can test this in Travis? Maybe rm -rf .git before running some tests?

[dougxc]

Don't we need to place a .mx_vcs_root file in the root directory?

[zakkak]

Is there some way we can test this in Travis? Maybe rm -rf .git before running some tests?

There is this graalvm/mx#216

Don't we need to place a .mx_vcs_root file in the root directory?

No it works both with .mx_vcs_root and ci.hocon

[dougxc]

There is this graalvm/mx#216

I would suggest moving/copying that gate task to the graal repo itself so that it is run for every Graal change, not just every mx change (which are less frequent).

No it works both with .mx_vcs_root and ci.hocon

At some point, I think we want to break the unnatural coupling to the existence of ci.hocon so would prefer that Graal has its own .mx_vcs_root file.

[zakkak]

@dougxc thanks for the feedback I fixed the comments in e961575 (not a travis user so please let me know if there is a better way to achieve this)