Log Message:
update to verilog-0.8.

The current release is a considerable improvement over the previous stable
release. It includes 20 months of fixes and language coverage improvements.
For a complete history of changes, see the release notes for individual
snapshots between the 0.7 and 0.8 releases found at
ftp://ftp.icarus.com/pub/eda/verilog/snapshots/pre-0.8

A brief list of highlights:

 - Support for advanced standard data types such as real,
 - Lots more language support in general,
 - Kernel of an extensible, interactive debugger is new,
 - More complete support for user supplied system functions and tasks,
   including PLI system functions with various return value types,
 - Better standards compliance for core system tasks and functions in
   general, including some Verilog 2001 file I/O support, and
 - Performance improvements in general.