Fix bugs in sparc PLT profiling register management, and add sparc sotruss support.

Fix bugs in sparc PLT profiling register management, and add sparc sotruss support.

	* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_rela): Protect local
	variables with appropriate CPP guards.
	* sysdeps/sparc/sparc32/dl-trampoline.S: Propagate the stack_ptr from the
	frame pointer, not the stack pointer.  Correct layout comments.  Fix test
	on resulting framesize and the management of the outregs buffer for pltexit.
	Preserve floating point return values across _dl_call_pltexit call.
	* sysdeps/sparc/sparc64/dl-trampoline.S: Fix test on resulting
	framesize and the management of the outregs buffer for pltexit.
	Preserve floating point return values across _dl_call_pltexit
	call.
	* elf/sotruss-lib.c (la_sparc32_gnu_pltenter, la_sparc64_gnu_pltenter,
	la_sparc32_gnu_pltexit, la_sparc64_gnu_pltexit): New functions.
	(print_exit): Fix format string for return register value.