Returns the DW_LANG_ code for this DIE's DWARF unit, if it exists.
Declared in <llvm/DebugInfo/DWARF/DWARFDie.h>
<llvm/DebugInfo/DWARF/DWARFDie.h>
std::optional<uint64_t> getLanguage() const;
The DW_LANG_ code, or std::nullopt if it does not exist.