[uClibc] _GLIBCPP_USE_NAMESPACES obsoleted

[Peter S. Mazinger]

Hello!

include/wchar.h and include/sys/cdefs.h check for
_GLIBCPP_USE_NAMESPACES. According to listdc++-v3/Changelog-2000 this was
removed in 2000, so maybe it should be combined w/ some gcc_version_check 
too, if needed.

Peter

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Peter S. Mazinger <ps dot m at gmx dot net>           ID: 0xA5F059F2
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