https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65733
--- Comment #12 from Jack Howarth <howarth.at.gcc at gmail dot com> --- It appears that clang 3.5 and later defaults to setting the CIE version to dwarf2 in the absence of -g. This behavior can't be overridden by passing -gdwarf-3 in the absence of -g. However the gcc configure test failure can be suppressed under clang by appending -gdwarf-2 instead (to downgrade the CIE version to dwarf3 in the presence of -g).
