[rfc] [00/12] Get rid of current_gdbarch

[Markus Deuling <deuling@de.ibm.com>]

Hi,

this and the next patch sets are another step in the direction of per-frame architecture. To achieve that
goal GDB needs to get rid of the global variable current_gdbarch. This set of 12 patches replaces (trivial to 
replace occurences of) current_gdbarch by appropriate methods like get_frame_arch or get_regcache_arch etc.

Currently get_frame_arch just returns current_gdbarch but this will be replaced by later patches.

I tested this patch set on x86 (native and remote), ppc and ppc64 by compiling and running the testsuite. I also did a gdb_mbuild with all
targets to make sure it compiles.

Some later patches will be non-trivial and hard for me to test due to lack of those machines. It would be great if 
some of you could test patches for different archs like mips, arm, etc. but this will still take a while.

This patch set replaces some of the current_gdbarch's in following files:

* aix-thread.c
* arm-tdep.c
* alpha-{linux-nat,nat,tdep}.c
* frame.c
* i386-tdep.c
* mips-tdep.c
* ppc-linux-nat.c
* rs6000-tdep.c
* sh[64]-tdep.c
* xtensa-tdep.c
* remote.c

Is this ok?

-- 
Markus Deuling
GNU Toolchain for Linux on Cell BE
deuling@de.ibm.com