The `AddDebugInfo` pass currently has a dependency on the `DLTI` MLIR
dialect caused by a call to the `fir::support::getOrSetMLIRDataLayout()`
utility function.
This dependency is not captured in the pass definition. This patch adds
the dependency and simplifies several unit tests that had to explicitly
use the `DLTI` dialect to prevent the missing dependency from causing
compiler failures.
The debug information generated by flang did not handle the cases where
dimension or lower bounds of the arrays were variable. This PR fixes
this issue. It will help distinguish assumed size arrays from cases
where array size are variable. It also handles the variable lower bounds
for assumed shape arrays.
Fixes#98879.
