Reland "Roll clang n332890-c2443155-1 : n333938-3a6da112-1."

This is a reland of b21c79dc

Original change's description:
> Roll clang n332890-c2443155-1 : n333938-3a6da112-1.
> 
> Ran `./tools/clang/scripts/upload_revision.py 3a6da1122b990386edeba0987d0d1fdc9c8dc53d`.
> 
> Bug: 1030664
> Change-Id: I229bf8fd0d65fcacdab5f002220d1350b38aedb6
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1966387
> Auto-Submit: Reid Kleckner <rnk@chromium.org>
> Commit-Queue: Nico Weber <thakis@chromium.org>
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#727069}

Bug: 1030664
Change-Id: I7a7fdcf7b0c6bd22f4840748318f7180931ea468
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1979068Reviewed-by: Hans Wennborg <hans@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#727096}

build/config/compiler/BUILD.gn

@@ -632,9 +632,9 @@ config("compiler") {
           ]
         }
 
-        if (llvm_force_head_revision) {
-          # Disable TypePromotion to see if that fixes the ToT bots.
-          # TODO(crbug.com/1033863): Get this fixed upstream.
+        # Disable TypePromotion to work around compiler crash in Android LTO builds.
+        # TODO(crbug.com/1033863): Get this fixed upstream.
+        if (target_os != "chromeos") {
           ldflags += [
             "-Wl,-mllvm",
             "-Wl,-disable-type-promotion=true",
@@ -1536,6 +1536,9 @@ config("default_warnings") {
 
           # TODO(https://crbug.com/1028110): Evaluate and possible enable.
           "-Wno-deprecated-copy",
+
+          # TODO(https://crbug.com/1031169): Clean up and enable.
+          "-Wno-misleading-indentation",
         ]
 
         if (is_win) {
@@ -1549,13 +1552,6 @@ config("default_warnings") {
           # TODO(https://crbug.com/995993): Clean up and enable.
           "-Wno-implicit-fallthrough",
         ]
-
-        if (llvm_force_head_revision) {
-          cflags += [
-            # TODO(https://crbug.com/1031169): Clean up and enable.
-            "-Wno-misleading-indentation",
-          ]
-        }
       }
     }
   }

tools/clang/scripts/update.py

@@ -39,8 +39,8 @@ import zipfile
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://chromium.googlesource.com/chromium/src/+/master/docs/updating_clang.md
 # Reverting problematic clang rolls is safe, though.
-CLANG_REVISION = 'c2443155a0fb245c8f17f2c1c72b6ea391e86e81'
-CLANG_SVN_REVISION = 'n332890'
+CLANG_REVISION = '3a6da1122b990386edeba0987d0d1fdc9c8dc53d'
+CLANG_SVN_REVISION = 'n333938'
 CLANG_SUB_REVISION = 1
 
 PACKAGE_VERSION = '%s-%s-%s' % (CLANG_SVN_REVISION, CLANG_REVISION[:8],