[clangd] Move non-clang base pieces into separate support/ lib. NFCI

Summary:
This enforces layering, reduces a sprawling clangd/ directory, and makes life
easier for embedders.

Reviewers: kbobyrev

Subscribers: mgorny, ilya-biryukov, javed.absar, MaskRay, jkorous, arphaman, jfb, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D79014
diff --git a/clang-tools-extra/clangd/JSONTransport.cpp b/clang-tools-extra/clangd/JSONTransport.cpp
index a925473..fa86baf 100644
--- a/clang-tools-extra/clangd/JSONTransport.cpp
+++ b/clang-tools-extra/clangd/JSONTransport.cpp
@@ -5,11 +5,11 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
-#include "Cancellation.h"
-#include "Logger.h"
 #include "Protocol.h" // For LSPError
-#include "Shutdown.h"
 #include "Transport.h"
+#include "support/Cancellation.h"
+#include "support/Logger.h"
+#include "support/Shutdown.h"
 #include "llvm/Support/Errno.h"
 #include "llvm/Support/Error.h"