PR c++/50437
	* cp-tree.h (struct tree_lambda_expr): Add closure field.
	(LAMBDA_EXPR_CLOSURE): New.
	* pt.c (tsubst_copy_and_build) [LAMBDA_EXPR]: Likewise.
	* semantics.c (build_lambda_object): Use it instead of TREE_TYPE.
	(begin_lambda_type, lambda_function, add_capture): Likewise.
	(add_default_capture, lambda_expr_this_capture): Likewise.

From-SVN: r179944