Roll clang 287780:288545.

Ran `tools/clang/scripts/upload_revision.py 288545`.

This brings in a regression for linux lld (bug 670397), but nobody uses that yet.
In return, it speeds up CFI blacklist processing, makes it possible to turn on blink
PCH use on Windows (would crash previously), and makes win/asan work in
component builds again.

BUG=670392
TBR=hans

Review-Url: https://codereview.chromium.org/2551603004
Cr-Commit-Position: refs/heads/master@{#436228}

tools/clang/scripts/update.py

@@ -27,14 +27,14 @@ 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 = '287780'
+CLANG_REVISION = '288545'
 
 use_head_revision = 'LLVM_FORCE_HEAD_REVISION' in os.environ
 if use_head_revision:
   CLANG_REVISION = 'HEAD'
 
 # This is incremented when pushing a new build of Clang at the same revision.
-CLANG_SUB_REVISION=2
+CLANG_SUB_REVISION=1
 
 PACKAGE_VERSION = "%s-%s" % (CLANG_REVISION, CLANG_SUB_REVISION)