* Move compiler/ under vlib/compiler/ .
* Add a minimal compiler/main.v driver program.
* Cleanup compiler/main.v .
* Make most compiler tests pass again.
* Apply the fix by @joe-conigliaro , so that the rest of the compiler tests are fixed too.
* Thanks to @avitkauskas, now the vlib/vcompiler/tests/str_gen_test.v test does not need to be special cased anymore.
* Reapply @joe-conigliaro fix for vgen.
* v test: support for running 'v test folder/' .
* Support passing multiple folders and also single _test.v files to 'v test' .
* Update vhelp too, with descriptions of v test folder/ and v -stats .
* Fix running `v test v` from outside the root of the v tree.
* compiler: extract and cleanup error handling functionality into its own file compiler/compile_errors.v
* compiler: implement p.error_with_token_index and p.warn_with_token_index and use them. Fix tests.
* tools/performance_compare: add a 'Source lines in compiler/' line
* MSVC does not have STDOUT_FILENO nor STDERR_FILENO ...