Use a dyn_cast to avoid a crash when the TypeLoc is not a ConstantArrayTypeLoc.
rdar://13153516


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174477 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 8db1831..800f64c 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -5777,10 +5777,11 @@
       TInfo = TDL->getTypeSourceInfo();
       continue;
     }
-    ConstantArrayTypeLoc CTL = cast<ConstantArrayTypeLoc>(TL);
-    const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL.getSizeExpr());
-    if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
-      return false;
+    if (const ConstantArrayTypeLoc *CTL = dyn_cast<ConstantArrayTypeLoc>(&TL)) {
+      const Expr *SizeExpr = dyn_cast<IntegerLiteral>(CTL->getSizeExpr());
+      if (!SizeExpr || SizeExpr->getExprLoc().isMacroID())
+        return false;
+    }
     break;
   }