S390: Support PLT and GOT references in check-localplt.

on s390x the test elf/check-localplt is failing after recent commits:
"elf: Do not use memalign for TCB/TLS blocks allocation [BZ #17730]"
"elf: Avoid using memalign for TLS allocations [BZ #17730]"
"elf: dl-minimal malloc needs to respect fundamental alignment"
due to "Missing required PLT reference: ld.so: __libc_memalign".

After the commits __libc_memalign is only called in elf/dl-minimal.c in
malloc() function in ld.so and gcc -O2/-O3 leads to R_390_GLOB_DAT
instead of R_390_JMP_SLOT. __libc_memalign is called via
function-pointer loaded from GOT instead of calling via a plt-stub. In
this case there is the R_390_GLOB_DAT relocation in section .rela.dyn
instead of R_390_JMP_SLOT in .rela.plt.
This patch marks ld.so: __libc_memalign with R_390_GLOB_DAT in
localplt.data to allow both relocations.
If build with -fno-optimize-sibling-calls or on s390(31bit) a
R_390_JMP_SLOT is generated.

ChangeLog:

	* sysdeps/unix/sysv/linux/s390/localplt.data: Mark
	ld.so: __libc_memalign with "+ RELA R_390_GLOB_DAT".

1 files changed, 5 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 73c9073ee2..d74100f2bb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-09-06  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
+	* sysdeps/unix/sysv/linux/s390/localplt.data: Mark ld.so:
+	__libc_memalign with "+ RELA R_390_GLOB_DAT".
+
 2016-09-06  Florian Weimer  <fweimer@redhat.com>
 
 	Convert malloc to __libc_lock.  Automated part, using this Perl