configure.ac: Allow both powerpc*-*-linux* and powerpc*-*-gnu* for long double compat...

configure.ac: Allow both powerpc*-*-linux* and powerpc*-*-gnu* for long double compatibility.

gcc:
	* configure.ac: Allow both powerpc*-*-linux* and powerpc*-*-gnu*
	for long double compatibility.
	* configure: Regenerate.

libstdc++-v3:
	* configure.ac: Allow both powerpc*-*-linux* and powerpc*-*-gnu*
	for long double compatibility.
	* configure: Regenerate.
	* src/complex_io.cc, src/istream-inst.cc, src/ostream-inst.cc:
	Condition some _GLIBCXX_LDBL_COMPAT calls on _GLIBCXX_USE_WCHAR_T.

From-SVN: r123972