Introduce common-types.h

Introduce common-types.h

This introduces common-types.h.  This file defines various standard
types used by gdb and gdbserver.

Currently these types are conditionally defined based on GDBSERVER.
The long term goal is to remove all such tests; however, this is
difficult as currently gdb uses definitions from BFD.  In the meantime
this is still a step in the right direction.

gdb/ChangeLog:

	* common/common-types.h: New file.
	* Makefile.in (HFILES_NO_SRCDIR): Add common/common-types.h.
	* common/common-defs.h: Include common-types.h.
	* defs.h (gdb_byte, CORE_ADDR, CORE_ADDR_MAX, LONGEST)
	(ULONGEST): Remove.

gdb/gdbserver/ChangeLog:

	* server.h: Add static assertion.
	(gdb_byte, CORE_ADDR, LONGEST, ULONGEST): Remove.