Roll clang llvmorg-12-init-5035-gd0abc757-2 : llvmorg-12-init-5627-gf086e85e-1.

Ran `./tools/clang/scripts/upload_revision.py f086e85eea94a51eb42115496ac5d24f07bc8791`.

Bug: 1126953
Change-Id: I5448a7bb6b4a17a8e45da1ab51f53f8dd0122830
Cq-Include-Trybots: chromium/try:chromeos-amd64-generic-cfi-thin-lto-rel
Cq-Include-Trybots: chromium/try:dawn-win10-x86-deps-rel
Cq-Include-Trybots: chromium/try:linux-chromeos-dbg
Cq-Include-Trybots: chromium/try:linux_angle_deqp_rel_ng
Cq-Include-Trybots: chromium/try:linux_chromium_cfi_rel_ng
Cq-Include-Trybots: chromium/try:linux_chromium_chromeos_asan_rel_ng
Cq-Include-Trybots: chromium/try:linux_chromium_chromeos_msan_rel_ng
Cq-Include-Trybots: chromium/try:linux_chromium_compile_dbg_32_ng
Cq-Include-Trybots: chromium/try:linux_chromium_msan_rel_ng
Cq-Include-Trybots: chromium/try:mac-arm64-rel,mac_chromium_asan_rel_ng
Cq-Include-Trybots: chromium/try:win-angle-deqp-rel-64
Cq-Include-Trybots: chromium/try:win-asan,win7-rel,win-angle-deqp-rel-32
Cq-Include-Trybots: chrome/try:iphone-device,ipad-device
Cq-Include-Trybots: chrome/try:linux-chromeos-chrome
Cq-Include-Trybots: chrome/try:win-chrome,win64-chrome,mac-chrome
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2407433Reviewed-by: Hans Wennborg <hans@chromium.org>
Auto-Submit: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806621}

build/config/compiler/BUILD.gn

@@ -501,6 +501,12 @@ config("compiler") {
       "-mllvm",
       "-instcombine-lower-dbg-declare=0",
     ]
+
+    cflags += [
+      # TODO(https://crbug.com/1127713): Investigate, remove.
+      "-mllvm",
+      "-enable-dse-memoryssa=false",
+    ]
   }
 
   # C11/C++11 compiler flags setup.

tools/clang/scripts/update.py

@@ -38,8 +38,8 @@ import zipfile
 # https://chromium.googlesource.com/chromium/src/+/master/docs/updating_clang.md
 # Reverting problematic clang rolls is safe, though.
 # This is the output of `git describe` and is usable as a commit-ish.
-CLANG_REVISION = 'llvmorg-12-init-5035-gd0abc757'
-CLANG_SUB_REVISION = 2
+CLANG_REVISION = 'llvmorg-12-init-5627-gf086e85e'
+CLANG_SUB_REVISION = 1
 
 PACKAGE_VERSION = '%s-%s' % (CLANG_REVISION, CLANG_SUB_REVISION)
 RELEASE_VERSION = '12.0.0'