x86: Properly handle IFUNC function pointer reference

Update

commit 68c4956b
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Tue Apr 26 09:08:54 2022 -0700

    x86: Properly handle function pointer reference

to properly handle IFUNC function pointer reference.  Since IFUNC symbol
value is only known at run-time, set pointer_equality_needed for IFUNC
function pointer reference in PDE so that it will be resolved to its PLT
entry directly.

bfd/

	PR ld/29216
	* elf32-i386.c (elf_i386_scan_relocs): Set pointer_equality_needed
	for IFUNC function pointer reference in PDE.
	* elf64-x86-64.c (elf_x86_64_scan_relocs): Likewise.

ld/

	PR ld/29216
	* testsuite/ld-ifunc/ifunc.exp: Run PR ld/29216 test.
	* testsuite/ld-ifunc/pr29216.c: New file.

(cherry picked from commit 98a1627f)