[MemorySSA] Disable checkClobberSanity for SkipSelfWalker.

Sanity will fail for this, since we're exploring getting a clobber
further than the sanity check expects.
Ideally we need to teach the sanity check to differentiate between the
two walkers based on the SkipSelf bool in the query.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350895 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemorySSA.cpp b/lib/Analysis/MemorySSA.cpp
index e471ec7..6a5567e 100644
--- a/lib/Analysis/MemorySSA.cpp
+++ b/lib/Analysis/MemorySSA.cpp
@@ -918,7 +918,8 @@
     }
 
 #ifdef EXPENSIVE_CHECKS
-    checkClobberSanity(Current, Result, Q.StartingLoc, MSSA, Q, AA);
+    if (!Q.SkipSelfAccess)
+      checkClobberSanity(Current, Result, Q.StartingLoc, MSSA, Q, AA);
 #endif
     return Result;
   }