r273910 build failure if <sys/_umtx.h> is out-of-date

Hi!

I have the following error when building HEAD:

---8<---
cc   -O2 -pipe
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/include
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/../../include -I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/sparc64
-DNLS -fexceptions
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/sparc64/sys
-D__DBINTERFACE_PRIVATE
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/../../contrib/gdtoa
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/../../contrib/libc-vis
-DINET6
-I/usr/obj/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/resolv
-D_ACL_PRIVATE -DPOSIX_MISTAKE
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/../libmd
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/../../contrib/jemalloc/include
-DMALLOC_PRODUCTION
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/../../contrib/tzcode/stdtime
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/stdtime
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/locale
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/sparc64/fpu
-DBROKEN_DES -DPORTMAP -DDES_BUILTIN
-I/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/rpc -DYP
-DNS_CACHING -DSYMBOL_VERSIONING -std=gnu99 -fstack-protector
-Wsystem-headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized
-Wno-pointer-sign   -c cancelpoints_sem_new.c -o cancelpoints_sem_new.o
In file included from cancelpoints_sem_new.c:47:
/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc/../../include/semaphore.h:41:
error: field '_kern' has incomplete type
cancelpoints_sem_new.c:66: error: 'USEM_MAX_COUNT' undeclared here (not
in a function)
cc1: warnings being treated as errors
cancelpoints_sem_new.c: In function '_sem_getvalue':
cancelpoints_sem_new.c:335: warning: implicit declaration of function
'USEM_COUNT'
cancelpoints_sem_new.c: In function 'usem_wake':
cancelpoints_sem_new.c:342: error: 'UMTX_OP_SEM2_WAKE' undeclared (first
use in this function)
cancelpoints_sem_new.c:342: error: (Each undeclared identifier is
reported only once
cancelpoints_sem_new.c:342: error: for each function it appears in.)
cancelpoints_sem_new.c: In function 'usem_wait':
cancelpoints_sem_new.c:361: error: 'UMTX_OP_SEM2_WAIT' undeclared (first
use in this function)
cancelpoints_sem_new.c: In function '_sem_post':
cancelpoints_sem_new.c:445: error: 'USEM_HAS_WAITERS' undeclared (first
use in this function)
*** Error code 1

Stop.
make[4]: stopped in
/mnt/home/dumbbell/Projects/freebsd/src/SVN/head/lib/libc
*** Error code 1
---8<---

The problem is that the installed version of <sys/_umtx.h> is
out-of-date compared to the version in the source tree. I guess it's
supposed to pick the version in the source tree, but I'm not sure what's
the correct way of doing this.

FYI, this is with base gcc on sparc64. World was updated on August 6.

-- 
Jean-Sébastien Pédron