[0/7] Implement per-type architecture

[Ulrich Weigand]

Hello,

this set of 7 patches implements per-type architecture.  The series applies
on top of the various patches I posted earlier today.

After all patches are applied, every type in GDB's type system is either:
 - an objfile-related type allocated on the objfile obstack
   (these are indirectly associated with the objfile architecture)
or
 - an architecture-related type allocated on the heap

A new routine get_type_arch () will retrieve the associated architecure
for each type.

The first five patches in this series remove the remaining global types
and replace them by architecture-related types.

The sixth patch introduces new APIs to create per-gdbarch types and
updates all users.

The last patch then uses the new get_type_arch call in various places
to remove references to current_gdbarch.

The whole series was tested on amd64-linux, powerpc64-linux, spu-elf,
s390-ibm-linux and s390x-ibm-linux with no regressions.

All in all, this approach does appear to be simpler overall than the
previous approach to introduce per-value architecture.  I'd like to
go on with this version instead.  Comments are welcome!

Bye,
Ulrich



-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com