453e4102bd
This PR builds on the https://github.com/llvm/llvm-project/pull/158314 and adds the lowering support for `-gdwarf-N` flag. The changes to pass the information to `AddDebugInfo` pass are mostly mechanical. The `AddDebugInfo` pass adds `ModuleFlagsOp` in the module which gets translated to correct llvm metadata during mlir->llvmir translation. There is minor correction where the version is set to 0 in case no -debug-version flag is provided. Previously it was set to 2 in this case due to misreading of clang code.
Flang Integration Tests
This directory can be used to add Integration tests involving multiple stages of the compiler (for eg. from Fortran to LLVM IR). It should not contain executable tests. We should only add tests here sparingly and only if there is no other way to test. Repeat this message in each test that is added to this directory and sub-directories.