Silence static analyzer issue by documenting that in this context
that a DeclRefExpr can never return a null decl.  We possibly should
hoist this into getDecl() itself.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165841 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp b/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp
index b8b7c36..5cd6194 100644
--- a/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp
+++ b/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp
@@ -270,6 +270,7 @@
 
   // Emit the error.  First figure out which DeclRefExpr in the condition
   // referenced the compared variable.
+  assert(drInc->getDecl());
   const DeclRefExpr *drCond = vdLHS == drInc->getDecl() ? drLHS : drRHS;
 
   SmallVector<SourceRange, 2> ranges;