Are you thinking of some other file? sinfo.ad[sb] barely mentions
Source_Ptr at all: Only in two functions to get/set the End_Span,
neither of looks like they would need to be changed when converting
to source_location!
Sorry, indeed I was: sinput.ad[bs].
The gain is that alternative solutions require mapping between two
encodings for source locations. Plus better integration between Ada
and the rest of the compilers, which *we* think is desirable. Plus
using source_location is probably faster, considering what you have to
go through in Sloc_to_locus (even *before* switching to
source_location.