PR c++/9335
gcc/cp:
	* init.c (constant_value_1): Treat error_mark_node as a constant
	if DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P is set.
	* cvt.c (ocp_convert): Handle getting error_mark_node from
	integral_constant_value.
	* decl.c (compute_array_index_type): Likewise.
gcc/testsuite:
	* lib/prune.exp: Prune "skipping N instantiation contexts".

From-SVN: r158586