constexpr: converted constant expression handling for enumerator values, case
values and non-type template arguments of integral and enumeration types.

This change causes some legal C++98 code to no longer compile in C++11 mode, by
enforcing the C++11 rule that narrowing integral conversions are not permitted
in the final implicit conversion sequence for the above cases.

llvm-svn: 148439
diff --git a/clang/test/SemaCXX/enum-scoped.cpp b/clang/test/SemaCXX/enum-scoped.cpp
index aed8f08..791fcf1 100644
--- a/clang/test/SemaCXX/enum-scoped.cpp
+++ b/clang/test/SemaCXX/enum-scoped.cpp
@@ -39,7 +39,7 @@
 enum class E4 {
   e1 = -2147483648, // ok
   e2 = 2147483647, // ok
-  e3 = 2147483648 // expected-error{{value is not representable}}
+  e3 = 2147483648 // expected-error{{enumerator value evaluates to 2147483648, which cannot be narrowed to type 'int'}}
 };
 
 enum class E5 {