in doc and tests.

They need to be hashable to put into a frozenset.

* Introduce prioritize_loops as a replacement for set_loop_priority
* Kernels now store a frozenset of such priority constraints
* The scheduler builds priority tiers taking all these into account
* Deprecate set_loop_priority

Use the __restrict__ qualifier instead of the restrict keyword

`restrict` is keyword in C, but in C++ there is only a type qualifier `__restrict__`.
To my knowledge, the latter is available in both languages.

See merge request !12

Process single-writer heuristic early, deprecate late single-writer resolution



See merge request !10

`restrict` is keyword in C, but in C++ there is only a type qualifier `__restrict__`.
To my knowledge, the latter is available in both languages.

Allow subclassing of TemporaryVariable, by passing kwargs through

Shovelling additional data in the underlying Record requires
TemporaryVariable to pas through any unrecognized keyword arguments.
ArrayBase will check whether these are allowed through
allowed_extra_kwargs.

See merge request !11

Shovelling additional data in the underlying Record requires
TemporaryVariable to pas through any unrecognized keyword arguments.
ArrayBase will check whether these are allowed through
allowed_extra_kwargs.

Add implementation of constant args to CAST

Const args fix



See merge request !9

Also fix default priority for NoOpInstruction

The default priority is 0 not None.
Again, this could be fixed in NoOpInstruction, but I consider
this fix to be the better one.

I just wanted to push this on the old branch, but I missed you by some minutes...
Btw, is NoOpInstruction fully implemented or is this WIP (BarrierInstruction definitely seems WIP)?

See merge request !7