Handle dependent types/exprs in static_assert expressions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@66997 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 273b5ed..e34412e 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -1044,6 +1044,7 @@
 }
 
 static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
+  assert(!E->isValueDependent() && "Should not see value dependent exprs!");
   if (!E->getType()->isIntegralType()) {
     return ICEDiag(2, E->getLocStart());
   }