Hi,

D uses modules (DW_TAG_module), but to separate the namespace of every
source file.  Modules can be imported into each other, either publicly
or privately (DW_TAG_imported_module).  Or declarations can be
selectively imported or renamed (DW_TAG_imported_decl).

This patch pretty much just extends the existing support for
namespaces/modules in C++/Fortran/Java to include language_d too.
However unlike Fortran/C++, the separator for qualified names is a
single dot.

This will need to be followed up with a patch to support looking up
symbols in D module 'namespaces'.  However I'm currently unsure
whether to either extend cp-namespace.c, or to go ahead with my
current fork (d-namespace.c), which copies only what's needed,
adjusting for D-specific symbol import logic.

Iain.