Bug 201915

this can be realiable reproduced on 2 of my box，both running 10.1-REL amd64：

➜  ~  /libexec/ld-elf.so.1   
[1]    82553 segmentation fault (core dumped)  /libexec/ld-elf.so.1
➜  ~  uname -a
FreeBSD xxx 10.1-RELEASE-p10 FreeBSD 10.1-RELEASE-p10 #0: Wed May 13 06:54:13 UTC 2015     root@amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  amd64

gdb /libexec/ld-elf.so.1 ./ld-elf.so.1.core 
GNU gdb 6.1.1 [FreeBSD]
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "amd64-marcel-freebsd"...(no debugging symbols found)...
Core was generated by `ld-elf.so.1'.
Program terminated with signal 11, Segmentation fault.
#0  0x000000000102b184 in ?? ()
(gdb) bt
#0  0x000000000102b184 in ?? ()
#1  0x0000000001021040 in ?? ()
#2  0x000000080123f1a8 in ?? ()
#3  0x00007fffffffe670 in ?? ()
#4  0x00007fffffffe668 in ?? ()
#5  0x00007fffffffe660 in ?? ()
#6  0x0000000000000011 in ?? ()
#7  0x000000080123f1b0 in ?? ()
#8  0x000000080123f000 in ?? ()
#9  0x0000000001021158 in ?? ()
#10 0x00007fffffffebd0 in ?? ()
#11 0x00007fffffffefcb in ?? ()
#12 0x000000000123d6a8 in ?? ()
#13 0x00007fffffffeac0 in ?? ()
#14 0x0000000001024473 in ?? ()
#15 0x0000000000000000 in ?? ()