[vhdl-200x-ft] Update to FT-14/15 for record element types and consistent slicin g/constraint syntax

Jim,

I finally realized what John was talking about with record element types.
If you have an array of records and want one of the record element types,
you need the 'ELEMENT attribute to apply to records as well. The new syntax
includes a parameter to specify the field name. For example,

type COMPLEX is
  record
    re : SIGNED;
    im : SIGNED;
  end record;
type COMPLEX_VECTOR is array (NATURAL range <>) of COMPLEX;

signal Data : COMPLEX_VECTOR(1 to 10).(re(7 downto 0), im(7 downto 0));
constant DATA_REAL_WIDTH : INTEGER := Data'ELEMENT'ELEMENT(re)'LENGTH;

Also, I changed the "aggregate_index_constraint" to use a period like the
proposed multi-level slice.

The updated document is attached.

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Ryan Hinton
L-3 Communications / Communication Systems - West
ryan.w.hinton@L-3com.com