PR 108297 points out that there are systems that use ELF but for which
the linker does not support the --build-id option.  This libbacktrace
patch skips --build-id tests when it doesn't work.  Bootstrapped and
ran libbacktrace tests on x86_64-pc-linux-gnu.  Committed to mainline.

Ian

PR libbacktrace/108297
* configure.ac: Test whether linker supports --build-id.
* Makefile.am: Only run --build-id tests if supported.
* configure, Makefile.in: Regenerate.