* rtl.h (CONST_DOUBLE_P): Define.
	(rtx_to_double_int): Declare.
	* emit-rtl.c (rtx_to_double_int): New function.
	* dwarf2out.c (insert_double): New function.
	(loc_descriptor, add_const_value_attribute): Clean up, use
	rtx_to_double_int and insert_double functions.

From-SVN: r158963