When upgrading, install the ELF runtime linkers before libraries.

This is required to prevent problems with nss modules that use libthr when
upgrading from releases prior to 10.1.

PR:		197366
Sponsored by:	DARPA, AFRL
Differential Revision:	D1790
Reviewed by:	cperciva
MFC after:	3 days

usr.sbin/freebsd-update/freebsd-update.sh

@@ -2828,18 +2828,27 @@ Kernel updates have been installed.  Please reboot and run
 		    grep -E '^[^|]+\|d\|' > INDEX-NEW
 		install_from_index INDEX-NEW || return 1
 
+		# Install new runtime linker
+		grep -vE '^/boot/' $1/INDEX-NEW |
+		    grep -vE '^[^|]+\|d\|' |
+		    grep -E '^/libexec/ld-elf[^|]*\.so\.[0-9]+\|' > INDEX-NEW
+		install_from_index INDEX-NEW || return 1
+
 		# Install new shared libraries next
 		grep -vE '^/boot/' $1/INDEX-NEW |
 		    grep -vE '^[^|]+\|d\|' |
+		    grep -vE '^/libexec/ld-elf[^|]*\.so\.[0-9]+\|' |
 		    grep -E '^[^|]*/lib/[^|]*\.so\.[0-9]+\|' > INDEX-NEW
 		install_from_index INDEX-NEW || return 1
 
 		# Deal with everything else
 		grep -vE '^/boot/' $1/INDEX-OLD |
 		    grep -vE '^[^|]+\|d\|' |
+		    grep -vE '^/libexec/ld-elf[^|]*\.so\.[0-9]+\|' |
 		    grep -vE '^[^|]*/lib/[^|]*\.so\.[0-9]+\|' > INDEX-OLD
 		grep -vE '^/boot/' $1/INDEX-NEW |
 		    grep -vE '^[^|]+\|d\|' |
+		    grep -vE '^/libexec/ld-elf[^|]*\.so\.[0-9]+\|' |
 		    grep -vE '^[^|]*/lib/[^|]*\.so\.[0-9]+\|' > INDEX-NEW
 		install_from_index INDEX-NEW || return 1
 		install_delete INDEX-OLD INDEX-NEW || return 1