gdbarch.h: Change gdbarch_info::tdep_info's type to void *

gdbarch.h: Change gdbarch_info::tdep_info's type to void *

As reported by Ulrich here:

  https://sourceware.org/ml/gdb-patches/2015-09/msg00604.html

The system compiler (gcc 4.1) in Centos 5 doesn't like that we cast to a
pointer to a type that doesn't exist.  I see no real value in using this
kind iof construct over just using void *.  So this patch changes the
tdep_info field to void * and removes the casts.  Even in C++, we
should not need an explicit cast when assigning to a void *.

gdb/ChangeLog:

	* gdbarch.sh (struct gdbarch_info): Change tdep_info's type to void *.
	* gdbarch.h: Regenerate.
	* i386-tdep.c (i386_gdbarch_init): Remove cast to
	struct gdbarch_tdep_info *.
	* mips-tdep.c (mips_gdbarch_init): Likewise.
	* ppc-linux-tdep (ppu2spu_sniffer): Likewise.
	* rs6000-tdep.c (rs6000_gdbarch_init): Likewise.
	* spu-multiarch.c (spu_gdbarch): Likewise.