Update prebuilt Clang to match Android kernel.

Bug: 132428451
Change-Id: I8f6e2cb23f381fc0c02ddea99b867e58e925e5be
diff --git a/linux-x64/clang/include/llvm/Analysis/MemorySSA.h b/linux-x64/clang/include/llvm/Analysis/MemorySSA.h
index 6200837..fa92fd3 100644
--- a/linux-x64/clang/include/llvm/Analysis/MemorySSA.h
+++ b/linux-x64/clang/include/llvm/Analysis/MemorySSA.h
@@ -1,9 +1,8 @@
 //===- MemorySSA.h - Build Memory SSA ---------------------------*- C++ -*-===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -404,6 +403,7 @@
 
   void resetOptimized() {
     OptimizedID = INVALID_MEMORYACCESS_ID;
+    setOperand(1, nullptr);
   }
 
   void print(raw_ostream &OS) const;
@@ -703,6 +703,7 @@
   ~MemorySSA();
 
   MemorySSAWalker *getWalker();
+  MemorySSAWalker *getSkipSelfWalker();
 
   /// Given a memory Mod/Ref'ing instruction, get the MemorySSA
   /// access associated with it. If passed a basic block gets the memory phi
@@ -774,9 +775,6 @@
   /// all uses, uses appear in the right places).  This is used by unit tests.
   void verifyMemorySSA() const;
 
-  /// Check clobber sanity for an access.
-  void checkClobberSanityAccess(const MemoryAccess *MA) const;
-
   /// Used in various insertion functions to specify whether we are talking
   /// about the beginning or end of a block.
   enum InsertionPlace { Beginning, End };
@@ -791,7 +789,6 @@
   void verifyDomination(Function &F) const;
   void verifyOrdering(Function &F) const;
   void verifyDominationNumbers(const Function &F) const;
-  void verifyClobberSanity(const Function &F) const;
 
   // This is used by the use optimizer and updater.
   AccessList *getWritableBlockAccesses(const BasicBlock *BB) const {
@@ -828,7 +825,9 @@
                                       const MemoryUseOrDef *Template = nullptr);
 
 private:
+  class ClobberWalkerBase;
   class CachingWalker;
+  class SkipSelfWalker;
   class OptimizeUses;
 
   CachingWalker *getWalkerImpl();
@@ -882,7 +881,9 @@
   mutable DenseMap<const MemoryAccess *, unsigned long> BlockNumbering;
 
   // Memory SSA building info
+  std::unique_ptr<ClobberWalkerBase> WalkerBase;
   std::unique_ptr<CachingWalker> Walker;
+  std::unique_ptr<SkipSelfWalker> SkipWalker;
   unsigned NextID;
 };