next: lowering to SDFG fails with compile-time domain outside the range of the target domain

[edopao]

The following validation error was observed in the lowering to SDFG, in two icon4py stencil tests, when using compile-time vertical domain:

tests/dycore/stencil_tests/test_compute_derived_horizontal_winds_and_ke_and_contravariant_correction.py::TestComputeDerivedHorizontalWindsAndKEAndHorizontalAdvectionofWAndContravariantCorrection::test_TestComputeDerivedHorizontalWindsAndKEAndHorizontalAdvectionofWAndContravariantCorrection[compile_time_domain-input_data0]
dace.sdfg.validation.InvalidSDFGEdgeError: Memlet subset negative out-of-bounds (at state lambda_entry, edge __tmp14[0:29020, -3:-3] -> [0:29020, 10:10] (__tmp14:None -> __tmp15:None))
FAILED
tests/dycore/stencil_tests/test_compute_perturbed_quantities_and_interpolation.py::TestComputePerturbedQuantitiesAndInterpolation::test_TestComputePerturbedQuantitiesAndInterpolation[compile_time_domain]
dace.sdfg.validation.InvalidSDFGEdgeError: Memlet subset negative out-of-bounds (at state stmt_4, edge __tmp67[0:19208, -17:-17] -> [0:19208, 10:10] (__tmp67:None -> __tmp68:None))
FAILED

This error was triggered by the following input confuguration:

nflatlev = 13
nflat_gradp = 27
grid.num_levels = 10 (in simple_grid, used by stencil tests)

Some computation did start or end at a vertical index outside the target domain [0, 10]. This resulted in an invalid memlet subset during the lowering of a concat_where expression.

We could simply fix this in the lowering to SDFG, by removing branches of concat_where expressions when they have empty domain. Alternately, we can create an IR pass to remove such branches before lowering to SDFG.

As a temporary workaround, the test configuration was updated to use vertical indices inside the target domain (see 48c9b08).