GNU libtool is documented to support -export-dynamic and GNU ld is
documented to support --export-dynamic. However, GCC isn't documented
to support them. While GCC does support -export-dynamic for backwards
compatibility, Clang doesn't support it and interprets it wrongly. This
causes warnings to be shown during linking because Clang splits it into
'-e xport-dynamic' and the linker can't find 'xport-dynamic' symbol.