[Windows] Introduce a switch for the `lldb-server` mode on Windows

Authored by aleksandr.urakov on Oct 10 2019, 5:21 AM.


[Windows] Introduce a switch for the lldb-server mode on Windows

This patch introduces a switch, based on the environment variable
LLDB_USE_LLDB_SERVER, to determine whether to use the ProcessWindows plugin
(the old way) or the lldb-server way for debugging on Windows.

Reviewers: labath, amccarth, asmith, stella.stamenova

Reviewed By: labath, amccarth

Subscribers: mstorsjo, abidh, JDevlieghere, lldb-commits, leonid.mashinskiy

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D68258

llvm-svn: 374325