Revert "Roll clang 346388-1:346388-4."

This reverts commit c03fc8e7.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Roll clang 346388-1:346388-4.
> 
> Ran `tools/clang/scripts/upload_revision.py 346388 4`.
> 
> Bug: 870331
> Change-Id: Ie2ebb3aa52bc757f4a0680cdbf8f060a030ce9a6
> Reviewed-on: https://chromium-review.googlesource.com/c/1344209
> Reviewed-by: Hans Wennborg <hans@chromium.org>
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Commit-Queue: Hans Wennborg <hans@chromium.org>
> Commit-Queue: Nico Weber <thakis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#610096}

TBR=thakis@chromium.org,hans@chromium.org,rnk@chromium.org,mmoroz@chromium.org

Change-Id: Ica508f221abd3f53dee66eb3f1937773c8947d27
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 870331
Reviewed-on: https://chromium-review.googlesource.com/c/1347104Reviewed-by: Gayane Petrosyan <gayane@chromium.org>
Commit-Queue: Gayane Petrosyan <gayane@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610111}

tools/clang/scripts/update.py

@@ -35,7 +35,7 @@ if use_head_revision:
   CLANG_REVISION = 'HEAD'
 
 # This is incremented when pushing a new build of Clang at the same revision.
-CLANG_SUB_REVISION=4
+CLANG_SUB_REVISION=1
 
 PACKAGE_VERSION = "%s-%s" % (CLANG_REVISION, CLANG_SUB_REVISION)