This avoids Coq distinguishing iProp and uPred (iResUR _) when it
should not.

(which are useful in Amin's logical relations development).

This also removes the double use of the name 'wp_fork' in both
program_logic/weakestpre and heap_lang/lifting.

Following the time anology of later, the step-index 0 corresponds does
not correspond to 'now', but rather to the end of time (i.e. 'last').

Make names more consistent with the rest of the development, make
definitions type classes opaque so that the proofmode does not unfold
then, declare timeless, persistent and proper instances.

This implements issue #3.

Since [inG] ranges over [cmraT]s, using an [ucmraT]s results in
[ucmra_cmraR] coercions that slow down type checking.

This commit improves the compilation time of thread_local.v by 40%.

By using the global ghost maps instead of our own ones.

It is not non-expansive, so not a function we should use.

This generalization is surprisingly easy in Iris 3.0, so I could not
resist not doing it :).

This makes stuff more uniform and also removes the need for the [inGFs]
type class. Instead, there is now a type class [subG Σ1 Σ2] which expresses
that a list of functors [Σ1] is contained in [Σ2].

I do not know why we have to split the rewrite here, but it seems we do.

This is probably due to a bug in the rewrite of ssreflect 1.6 which has
been fixed in ssreflect master.

I cannot reproduce the error of the CI builder on my machine with the
same version of Coq (8.5pl2).

And make it Typeclasses Opaque to ensure that we indeed do not do
so using the proof mode.

Instead of having connectives pvs0 and pvs1 we now have one connective
pvs that is indexed by a Boolean.

Use it to prove that tests/barrier_client and tests/heap_lang are adequate.