Do not add InterpolationOperator around constants

See merge request !54

Fix einsum in RefMassOperator

See merge request inducer/grudge!57

* skip when the dd_in == dd_out
* skip for constants

Allow POCL CI failures for now

See merge request !59

Add atan2 FunctionSymbol

See merge request !55

execution: fix map_if for scalars

See merge request !52

1D Fixes

See merge request !48

Remove cyclic dependencies in symbolic module

See merge request !49

The problem is that in 1D faces are 0D and so carry exactly no
useful information about which side of the element they may be
on.

To hack around that, this commit introduces a hacky operator
that hacks it. Less ambiguously, we just use the connection to
figure out which face we're on on set the normal to `+1` or `-1`
based on that

bind(): Fix bitrot associated with debug_flags

See merge request !47

Track leap Method->MethodBuilder change

See merge request !46

dagrt-fusion.py: Ensure output files get closed

See merge request !45