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

@@ -15,11 +15,11 @@
 # Copyright 2021 Tintri by DDN, Inc. All rights reserved.
 # Copyright 2021 OmniOS Community Edition (OmniOSce) Association.
 # Copyright 2023 Oxide Computer Company
 #
 
-SUBDIRS_i386 = i386 imc zen_umc
+SUBDIRS_i386 = i386 imc zen_umc xsave
 
 SUBDIRS =       \
                 cores \
                 ddi_ufm \
                 definit \

@@ -48,10 +48,11 @@
         clock_gettime \
         eventfd \
         odirectory \
         OS-6097 \
         ucontext \
+        getcontext_extd \
         writev
 
 CPPFLAGS += -D_REENTRANT
 PROGS32 = $(PROGS:%=%.32)
 PROGS64 = $(PROGS:%=%.64)