proc-service, extern "C"

proc-service, extern "C"

libthread_db.so calls symbols in the client (GDB), through the
proc-service interface.  These routines must have extern "C" linkage
so their symbol names are not mangled when GDB is built as a C++
program.  On the GDBserver side, we were missing fallback declarations for
all these symbols.

gdb/ChangeLog:
2015-02-27  Pedro Alves  <palves@redhat.com>

	* gdb_proc_service.h: Wrap with EXTERN_C_PUSH/EXTERN_C_POP.

gdb/gdbserver/ChangeLog:
2015-02-27  Pedro Alves  <palves@redhat.com>

	* gdb_proc_service.h: Wrap with EXTERN_C_PUSH/EXTERN_C_POP.
	[!HAVE_PROC_SERVICE_H] (struct ps_prochandle): Forward declare.
	[!HAVE_PROC_SERVICE_H] (ps_pdread, ps_pdwrite, ps_ptread)
	ps_ptwrite, ps_lgetregs, ps_lsetregs, ps_lgetfpregs)
	(ps_lsetfpregs, ps_getpid)
	(ps_get_thread_area, ps_pglobal_lookup, ps_pstop, ps_pcontinue)
	(ps_lstop, ps_lcontinue, ps_lgetxregsize, ps_lgetxregs)
	(ps_lsetxregs, ps_plog): Declare.