* ppc-linux-tdep.c: Include "solib.h", "solist.h", "exceptions.h",

	* ppc-linux-tdep.c: Include "solib.h", "solist.h", "exceptions.h",
	"arch-utils.h", and "spu-tdep.h".
	(spu_context_objfile, spe_context_lm_addr, spe_context_offset):
	New static variables.
	(spe_context_cache_ptid, spe_context_cache_address): Likewise.
	(ppc_linux_spe_context_lookup): New function.
	(ppc_linux_spe_context_inferior_created): Likewise.
	(ppc_linux_spe_context_solib_loaded): Likewise.
	(ppc_linux_spe_context_solib_unloaded): Likewise.
	(ppc_linux_spe_context): Likewise.
	(struct ppu2spu_cache, struct ppu2spu_data): New data types.
	(ppu2spu_prev_arch, ppu2spu_this_id, ppu2spu_prev_register,
	ppu2spu_unwind_register, ppu2spu_sniffer,
	ppu2spu_dealloc_cache): New functions.
	(ppu2spu_unwind): New static variable.
	(ppc_linux_init_abi): Install cross-architecture unwinder.
	(_initialize_ppc_linux_tdep): Attach to observers.

	* spu-tdep.c (struct spu2ppu_cache): New data type.
	(spu2ppu_prev_arch, spu2ppu_this_id, spu2ppu_prev_register,
	spu2ppu_sniffer, spu2ppu_dealloc_cache): New functions.
	(spu2ppu_unwind): New static variable.
	(spu_gdbarch_init): Install cross-architecture unwinder.