[analyzer] Specify the C++ standard in more tests.

Makes life easier for downstream developers with different default standard.

llvm-svn: 375308
diff --git a/clang/test/Analysis/sizeofpack.cpp b/clang/test/Analysis/sizeofpack.cpp
index 44c3bba..8c0ca02 100644
--- a/clang/test/Analysis/sizeofpack.cpp
+++ b/clang/test/Analysis/sizeofpack.cpp
@@ -1,5 +1,5 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection \
-// RUN:                    -verify %s
+// RUN:                    -std=c++14 -verify %s
 
 typedef __typeof(sizeof(int)) size_t;