CI: use WASM yosys instead of building our own.

Fixes #434.

.travis.yml

@@ -7,22 +7,15 @@ python:
   - "pypy3"
 cache:
   directories:
-    - "$HOME/.ccache"
     - "$HOME/.local"
-addons:
-  apt:
-    packages:
-      - gperf
+    - "$HOME/.cache/wasmtime"
 before_install:
-  - export PATH="/usr/lib/ccache:$HOME/.local/bin:$PATH"
-install:
-  - pip install coverage codecov pyvcd Jinja2
-  - git clone https://github.com/YosysHQ/yosys
-  - (cd yosys && if ! yosys -V || [ $(git rev-parse HEAD $(yosys -V | awk 'match($0,/sha1 ([0-9a-f]+)/,m) { print m[1] }') | uniq | wc -l) != 1 ]; then make CONFIG=gcc ENABLE_ABC=0 PREFIX=$HOME/.local install; fi)
-  - (git clone https://github.com/YosysHQ/SymbiYosys && cd SymbiYosys && make PREFIX=$HOME/.local install)
   - if ! yices -V; then (git clone https://github.com/SRI-CSL/yices2.git && cd yices2 && autoconf && ./configure --prefix=$HOME/.local && make && make install); fi
-script:
+  - pip install coverage codecov pyvcd Jinja2 yowasp-yosys nmigen-yosys
+  - export NMIGEN_USE_YOSYS=builtin YOSYS=yowasp-yosys
+install:
   - python setup.py develop
+script:
   - coverage run -m unittest discover
   - codecov
 matrix: