Since gold doesn't support INSERT in linker script:
https://sourceware.org/bugzilla/show_bug.cgi?id=21676
tst-split-dynreloc fails to link with gold. Check if linker supports
INSERT in linker script before using it.
* config.make.in (have-insert): New.
* configure.ac (libc_cv_insert): New. Set to yes if linker
supports INSERT in linker script.
(AC_SUBST(libc_cv_insert): New.
* configure: Regenerated.
* sysdeps/x86_64/Makefile (tests): Add tst-split-dynreloc only
if $(have-insert) == yes.
19f1a11e7e