dyn_load.c: Define ElfW (if needed) for all targets, not just GNU/Linux.

	* dyn_load.c: Define ElfW (if needed) for all targets,
	not just GNU/Linux.
	(GC_FirstDLOpenedLinkMap): Use it.
	(GC_register_dynamic_libraries_dl): Use it.
	* include/private/gcconfig.h: Define CPP_WORDSZ, ELF_CLASS
	for sparcv9.

From-SVN: r48086