* doublest.c (convert_doublest_to_floatformat): Rename

* doublest.c (convert_doublest_to_floatformat): Rename
floatformat_from_doublest.  Make static.
(convert_floatformat_to_doublest): Rename floatformat_to_doublest.
Make static.
(floatformat_to_doublest): New function.
(floatformat_from_doublest): New function.
(host_float_format, host_double_format, host_long_double_format):
New static variables.
(store_floating, extract_floating): Always use
floatformat_to_doublest and floatformat_from_doublest.
* doublest.h (HOST_LONG_DOUBLE_FORMAT): Delete macro.