Issues under raising opaque SSA-defined bounds to ISL

I have met the issues the raising pass produces MLIR loop bounds from opaque LLVM ssa values that isl cannot map to named symbolic parameters, leading to unexpected unnamed parametersand failure to infer kernel dimensions. And the raising pass segfaults on translation units containing loops whose bounds come from indirect memory accesses.

The output messages are:
Hundreds of `src/external/isl/isl_space.c:3351: unexpected unnamed parameters` or `found loop with positive increment and non-constant bounds`.