[MLIR][LLVM] Add flag to skip import of DICompositeType's elems (#89355)

This commit introduces a flag to allow skipping the potentially
recursive import of DICompositeType elements. This patch is essentially a
bandaid for the still broken recursive debug type import.

Some of our downstream inputs are produced by excessive usage of
template meta programming, and thus contain tens of thousands of types
that all participate in such recursions. Unfortunately, the series of
patches that introduces type support is not easily revertible due to
being around for a while now and Modular depending on it.

We can consider to revert this change once the type importer has show to
be very performant, but for now we are talking second vs hours to import
specific files.