[patch] Patches to reduce warnings in libstdc++

[Jonathan Wakely]

Some small cleanups. These won't interfere with any testing of
backports to gcc-6-branch before the release, so I'm committing them
now.

The first two remove some noise when using -Wsystem-headers:

    Avoid -Wsign-compare warnings in std::to_string()

        * include/ext/string_conversions.h (__stoa): Avoid -Wsign-compare
        warnings.

    Add attribute((unused)) in libstdc++ headers
    
        * include/bits/locale_facets.h (ctype::do_narrow): Add attribute to
        unused parameter.
        * include/bits/regex_automaton.h (_NFA::_M_insert_alt): Likewise.

The other two remove some noise when running the testsuite with
-Wpedantic, and tidy up some tests.

Tested x86_64-linux, committed to trunk.


-------------- next part --------------
A non-text attachment was scrubbed...
Name: patch.txt
Type: text/x-patch
Size: 18524 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20160418/16957466/attachment.bin>