PR fortran/90329
	* tree-core.h (struct tree_decl_common): Document
	decl_nonshareable_flag for PARM_DECLs.
	* tree.h (DECL_HIDDEN_STRING_LENGTH): Define.
	* calls.c (expand_call): Don't try tail call if caller
	has any DECL_HIDDEN_STRING_LENGTH PARM_DECLs that are or might be
	passed on the stack and callee needs to pass any arguments on the
	stack.
	* tree-streamer-in.c (unpack_ts_decl_common_value_fields): Use
	else if instead of series of mutually exclusive ifs.  Handle
	DECL_HIDDEN_STRING_LENGTH for PARM_DECLs.
	* tree-streamer-out.c (pack_ts_decl_common_value_fields): Likewise.

	* trans-decl.c (create_function_arglist): Set
	DECL_HIDDEN_STRING_LENGTH on hidden string length PARM_DECLs if
	len is constant.

From-SVN: r271285