This is a free continuation of #281 (closed).

Tasks

• patch gtkwave not to use linear search when loading GHW data
• generate a list of signals in layout for GHDL's --read-wave-opt

Rationale

Task 1 drastically reduces load time, but still the amount of data is huge and gtkwave crashes on OOM. Task 2 aims to reduce the amount of data so that only reasonable amounts of memory are needed.