The getDIESectionOffset function is not correct for split dwarf files
(and will probably be removed in D48009).
This patch implements correct section offset computation for split and
non-split compile units -- we first need to check if the referenced unit
is a skeleton unit, and if it is, we add the die offset to the full unit
base offset (as the full unit is the one which contains the die).
llvm-svn: 334402
Pavel Labath