This introduces a new psymtab_storage class, which holds all
psymbol-related objects that are independent of the objfile. (This
latter contraint explains why psymbol_map was not moved; though this
could still be done with some work.)
This patch does not yet change where psymtab allocation is done --
that comes later. This just wraps everything in a single object to
make further transformations simpler.
Note that a shared_ptr is used to link from the objfile to the
psymtab_storage object. The end goal here is to allow a given symbol
reader to simply attach to the psymtab_storage object to the BFD, then
reuse it in later invocations; shared_ptr makes this simple to reason
about.
gdb/ChangeLog
2019-01-10 Tom Tromey <tom@tromey.com>