Remove greedy wildcards from libstdc++ linker script

Remove greedy wildcards from libstdc++ linker script

The only symbols matched by std::e[a-q]* and std::e[s-z]* that are
supposed to be in the GLIBCXX_3.4 version are std::exception::* and
std::endl and std::ends. The latter two already have explicit patterns
matching them, so we just need to match std::exception::*.

This change ensures that any new symbols with a return type of
std::enable_if<...> are not added to the GLIBCXX_3.4 version.

	* config/abi/pre/gnu.ver: Tighten up greedy wildcards.

From-SVN: r276468