Support "-f" source file specification like verilator and icarus

[aolofsson]

One thing that would help me (and possibly others) get up to spee quickly would be if I could use the same source command file that I use for icarus and verilator (arguably the two most popular open source simulators) to feed the fpgamake tool. The argument would typically be "-f my.cmd".

During evaluation, either read the file list as specified in command file or read the constants first. (the constants parts has given me problems in chip and synthesis tools).

An example of the content of the command file can be seen here.

../../constants/hdl/simulation_constants.v
../../elink/hdl/elink_regmap.v
dv_elink_tb.v
-y .
-y ../../elink/hdl
-y ../../stubs/hdl
-y ../../common/hdl
-y ../../memory/hdl
-y ../../embox/hdl
-y ../../emmu/hdl

[jameyhicks]

This is a good idea -- I will implement it.

[jameyhicks]

What is the difference between verilator -f foo.vc and verilator -F foo.vc? The help message says the first one is handled "relatively".