8a9e767fa6
This is a fix for https://github.com/llvm/llvm-project/issues/134912 which is a problem with mapping `fir.boxchar<k>` type values to the target i.e an `omp.target` op. There really are two problems. Fixing the first exposed the second. The first problem is that OpenMP lowering of maps in `omp.target` in Flang cannot handle the mapping of a value that doesnt have a defining operation. In other words, a value that is a block argument. This is handled by mapping the value using a `MapInfoOp`. The second problem this fixes is that it adds bounds to `omp.map.info` ops that map `fir.char<k, ?>` types by extracting the length from the corresponding `fir.boxchar`