CI testing (#234)

* run test in CI
* make CI run
* fix some issues with paths on Windows
* avoid using float80
* add mingw64 ci
* fix path issue in tests
* add lld for mingw64 CI

test/src/tester.py

@@ -1,7 +1,7 @@
 #!/usr/bin/python
-import os, sys, shutil, subprocess
+import os, sys, shutil, subprocess, tempfile
 
-TEST_DIR = '/tmp/c3test/'
+TEST_DIR = tempfile.mkdtemp().replace('\\', '/') + '/c3test/'
 
 class Config:
     run_skipped = False