Fix PR c++/45200, c++/45293, c++/45558

gcc/cp/Changelog:
	PR c++/45200
	PR c++/45293
	PR c++/45558
	* tree.c (strip_typedefs): Strip typedefs from the context of
	TYPENAME_TYPEs.

gcc/testsuite/ChangeLog:
	PR c++/45200
	PR c++/45293
	PR c++/45558
	* g++.dg/template/typedef34.C: New test.
	* g++.dg/template/typedef35.C: New test.

From-SVN: r163929