#889 No support for annotating specparams from SDF file

[Martin Whitaker]

The 1364-2001 standard added the ability to annotate a value read from a SDF file onto a specparam, using the LABEL keyword in the SDF file. Currently Icarus Verilog neither supports this functionality nor recognises the keyword.

As this functionality is not widely supported by other simulators, I'm setting this to a low priority.