Verilog fuzzer to test the major Verilog compilers by generating random, valid
and deterministic Verilog.

It currently supports the following synthesis tools: Yosys, Xst, Vivado, Quartus
and the following simulator: Icarus Verilog.

The fuzzer generates combinational and behavioural Verilog to test the various
tools. The most notable constructs that are supported and generated are the
following:

- module definitions with parameter definitions, inputs and outputs
- module items, such as instantiations, continuous assignment, always blocks,
  initial blocks, parameter and local parameter declarations
- most expressions, for example concatenation, arithmetic operations, ternary
  conditional operator
- behavioural code in sequential always blocks
- behavioural control flow such as if-else and for loops
- declaration of wires and variables of any size, signed or unsigned
- bit selection from wires and variables