This commit enables building and testing js.exe for windows. Needed
libraries are built in CI, and tests for those which pass were added.
Tests for LibJS which don't require javascripttestrunner were added but
the rest need to wait for that to be ported to windows.
We now explicitly enabling support for the minimum libraries needed
to build and run the AK testsuite. 81/82 tests are running and
passing. The exception is LexicalPath, as some path behaviour on
Windows is different than Unix, so the current tests will have lots of
platform specific failures. The implementer of LexicalPathWindows
recommended windows-specific tests here, so I will do that in a
follow up.
