This change alters/corrects DwarfReader's way of determining the size of
linetable entries (i.e. their "range size"); the interface (e.g. to
ElfReader) stays the same. Prior to this, it was assumed that static
instructions within "the linetable" were sorted in ascending order. This
assumption turned out to be false, as every compilation unit's header has
its own linetable and the compilation unit headers are not sorted by their
static instructions.
Furthermore this change implements normalization of file names.
Change-Id: Ia4beb7bf9cfb6f1a499aeebd01228335b70ab52d