Add suport for DW_FORM_STR[1-4] that are introduced in DWARF5. Adapted patch by tamur.
Picking up patch by tamur: https://reviews.llvm.org/D75485
I've addressed the outstanding issues, i.e.:
- Adding test cases for each error case in parseCompileUnitHeader(StringRef Info)
- Changing the error message to reuse the message from Error in parseCompileUnitHeader(StringRef Info)
- Adapted tests (minor change: test error message, and added required header info to unsupported_cu_index_version.s)
As it seems (https://reviews.llvm.org/D77143) llvm-dwp does not yet support a compile unit index version of 5, which is used in DWARF5. Will investigate (any input is welcome) later. However, with this patch (originally from tamur), we can now generate dwps.