15254 %ymm registers not restored after signal handler
15367 x86 getfpregs() summons corrupting %xmm ghosts
15333 want x86 /proc xregs support (libc_db, libproc, mdb, etc.)
15336 want libc functions for extended ucontext_t
15334 want ps_lwphandle-specific reg routines
15328 FPU_CW_INIT mistreats reserved bit
15335 i86pc fpu_subr.c isn't really platform-specific
15332 setcontext(2) isn't actually noreturn
15331 need <sys/stdalign.h>
Change-Id: I7060aa86042dfb989f77fc3323c065ea2eafa9ad
Conflicts:
    usr/src/uts/common/fs/proc/prcontrol.c
    usr/src/uts/intel/os/archdep.c
    usr/src/uts/intel/sys/ucontext.h
    usr/src/uts/intel/syscall/getcontext.c

@@ -110,11 +110,11 @@
 
 /*
  * Guts of prgetprivsize.
  */
 int
-priv_prgetprivsize(prpriv_t *tmpl)
+priv_prgetprivsize(const prpriv_t *tmpl)
 {
         return (sizeof (prpriv_t) +
             PRIV_SETBYTES - sizeof (priv_chunk_t) +
             (tmpl ? tmpl->pr_infosize : priv_info->priv_infosize));
 }