Fix PR 4988 by removing an invalid assertion (a function can be referenced in
GRExprEngine::VisitDeclRefExpr without 'asLValue' being true).

llvm-svn: 82598
diff --git a/clang/lib/Analysis/GRExprEngine.cpp b/clang/lib/Analysis/GRExprEngine.cpp
index a6c3c66..735949c 100644
--- a/clang/lib/Analysis/GRExprEngine.cpp
+++ b/clang/lib/Analysis/GRExprEngine.cpp
@@ -1006,7 +1006,7 @@
     return;
 
   } else if (const FunctionDecl* FD = dyn_cast<FunctionDecl>(D)) {
-    assert(asLValue);
+    // This code is valid regardless of the value of 'isLValue'.
     SVal V = ValMgr.getFunctionPointer(FD);
     MakeNode(Dst, Ex, Pred, state->BindExpr(Ex, V),
              ProgramPoint::PostLValueKind);