[gold patch] Add configure check for IFUNC support in static glibc

[Cary Coutant <ccoutant at google dot com>]

Gold's configure script checks for IFUNC support by checking for
assembler support and for a glibc >= 2.11, but some versions of glibc
do not support IFUNC symbols in statically-linked binaries (depending
on how glibc was built). This patch adds a configure check for this
and a new automake conditional, IFUNC_STATIC. The configure check
looks for the symbol __rel_iplt_start or __rela_iplt_start in the
linked output from conftest.c.

Tested on x86_64 with glibc with static support and with glibc without
static support. OK to commit?

-cary

	* configure.ac: Check for glibc support for gnu_indirect_function
	support with static linking, setting automake conditional
	IFUNC_STATIC.
	* Makefile.in: Regenerate.
	* configure: Regenerate.

	* testsuite/Makefile.am (ifuncmain1static, ifuncmain2static)
	(ifuncmain4static, ifuncmain5static, ifuncmain7static): Add check
	for IFUNC_STATIC.
	* testsuite/Makefile.in: Regenerate.

Attachment: gold-ifunc-static-patch.txt
Description: Text document