(PCP-769) Fix permissions hacks

[MikaelSmith]

Applying permissions on Windows and using fs::permissions on Solaris
were both hacked around due to a faulty assumption that they were broken
on those platforms. The root cause of both issues was a static
initialization ordering issue.

Fix it by using a macro to alias the variable name, rather than
assigning from a global variable in another object. Unwind Windows and
Solaris hacks.

[MikaelSmith]

Tests running at https://jenkins-master-prod-1.delivery.puppetlabs.net/view/puppet-agent/view/ad-hoc/job/platform_puppet-agent_init-van-int_suite-daily-ad-hoc/107/.

[ekinanp]

There is a test in modules/task_test.cc that checks the permissions which still have the ifdefs (last one, tasks-cache/sha directory). Other than that, this looks good to me.

[puppetcla]

CLA signed by all contributors.

[MikaelSmith]

pxp-agent acceptance tests passed on redhat, ubuntu, windows, solaris. I'll see about Windows versions of the permissions tests.

[MikaelSmith]

Tests updated.

[mruzicka]

So the problem was the functions making use of the static variable were called before the variable was initialized?
I'm assuming they were called from an initialization of another static/global object.

[mruzicka]

👍

[MikaelSmith]

Not quite. The global variable was copying from other global variable before that one was initialized.

[mruzicka]

Ah, I see!