Revert "Merge pull request #444 from Microsoft/newCompilerLS"

This reverts commit ae5f4c26171cc56bdff56e2893dc8ac113596270, reversing
changes made to 2f963743c4da421cc0a2fbf00a209dfff7f9aac4.
Merge pull request #459 from Microsoft/revertLS1

Revert the previous language service merge.