* sysdeps/unix/sparc/sysdep.h (SPARC_PIC_THUNK): New macro.
(SETUP_PIC_REG): Use SPARC_PIC_THUNK and don't save and restore
%o7 across the call.
(SETUP_PIC_REG_LEAF): Do %o7 save/restore in this new macro
instead.
* sysdeps/unix/sysv/linux/sparc/sparc32/sysdep.h: Use
SETUP_PIC_REG_LEAF.
* sysdeps/unix/sysv/linux/sparc/sparc64/sysdep.h: Likewise.
* sysdeps/sparc/crti.S: Use SETUP_PIC_REG.
* sysdeps/sparc/crtn.S: Likewise.