Synchronize libstdc++ as dll changes to mainline version, preparatory to

Synchronize libstdc++ as dll changes to mainline version, preparatory to
adopting new "apply dllimport attribute to namespace" approach.

	* libstdc++-v3/src/Makefile.in: Synch to mainline.
	* libstdc++-v3/src/Makefile.am: Likewise.
	* libstdc++-v3/include/std/iostream: Likewise.
	* libstdc++-v3/include/std/stdexcept: Likewise.
	* libstdc++-v3/include/ext/concurrence.h: Likewise.
	* libstdc++-v3/include/bits/locale_classes.tcc: Likewise.
	* libstdc++-v3/include/bits/locale_facets.tcc: Likewise.
	* libstdc++-v3/include/bits/locale_classes.h: Likewise.
	* libstdc++-v3/include/bits/locale_facets.h: Likewise.
	* libstdc++-v3/include/bits/basic_ios.tcc: Likewise.
	* libstdc++-v3/include/bits/ios_base.h: Likewise.
	* libstdc++-v3/include/bits/istream.tcc: Likewise.
	* libstdc++-v3/include/bits/codecvt.h: Likewise.
	* libstdc++-v3/include/bits/ostream.tcc: Likewise.
	* libstdc++-v3/include/bits/sstream.tcc: Likewise.
	* libstdc++-v3/include/bits/c++config: Likewise.
	* libstdc++-v3/include/bits/basic_string.tcc: Likewise.
	* libstdc++-v3/include/bits/locale_facets_nonio.tcc: Likewise.
	* libstdc++-v3/include/bits/streambuf.tcc: Likewise.
	* libstdc++-v3/include/bits/fstream.tcc: Likewise.
	* libstdc++-v3/include/backward/strstream: Likewise.
	* libstdc++-v3/libsupc++/typeinfo: Likewise.
	* libstdc++-v3/libsupc++/exception: Likewise.
	* libstdc++-v3/libsupc++/new: Likewise.
	* libstdc++-v3/testsuite/lib/libstdc++.exp: Likewise.
	* libstdc++-v3/config/os/newlib/os_defines.h: Likewise.
	* libstdc++-v3/config/os/mingw32/os_defines.h: Likewise.

	* libstdc++-v3/include/profile/hashtable.h: Delete.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/cygwin-improvements@156349 138bc75d-0d04-0410-961f-82ee72b054a4