* sysdeps/unix/sysv/linux/sparc/sparc64/__start_context.S: New file.
* sysdeps/unix/sysv/linux/sparc/sparc64/makecontext.c
(__start_context): Declare.
(__makecontext_ret): Delete.
(__makecontext): Hook up __start_context instead of
__makecontext_ret.
* sysdeps/unix/sysv/linux/sparc/sparc64/Makefile
(sysdep_routines): Add __start_context when in stdlib.