PR c++/52343 - error with alias template as template template argument

PR c++/52343 - error with alias template as template template argument

In the example accompanying this patch, check_instantiated_arg tries
to ensure that a non-type template argument should be a constant if it
has integral or enumeration type.

The problem is that an alias template which type-id is, e.g, an
integer, looks like an argument that has integral/enumeration type:
its TREE_TYPE is an integer type.  So check_instantiated_arg
mistenkaly barks that this integral non-type argument is not a
constant.

Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.

gcc/cp/

	PR c++/52343
	* pt.c (check_instantiated_arg): Allow type template arguments.

gcc/testsuite/

	PR c++/52343
	* g++.dg/cpp0x/alias-decl-29.C: New test.

From-SVN: r194960