PR c++/51289 - ICE with alias template for bound template template parm

PR c++/51289 - ICE with alias template for bound template template parm

gcc/cp/

	PR c++/51289
	* cp-tree.h (TYPE_TEMPLATE_INFO): Rewrite this accessor macro to
	better support aliased types.
	(TYPE_ALIAS_P): Don't crash on TYPE_NAME nodes that are not
	TYPE_DECL.
	* pt.c (find_parameter_packs_r): Handle types aliases.
	(push_template_decl_real): Check for bare parameter packs in the
	underlying type of an alias template.

gcc/PR51289/gcc/testsuite/

	PR c++/51289
	* g++.dg/cpp0x/alias-decl-17.C: New test.

From-SVN: r182170