[DebugInfo] Dump values in .debug_loclists and .debug_rnglists according to the DWARF format (5/8).

The patch changes dumping of a unit_length field and offsets in headers
in .debug_loclists and .debug_rnglists sections so that they are printed
as 16-digit hex values if the contribution is in the DWARF64 format.

Differential Revision: https://reviews.llvm.org/D79997