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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148439 91177308-0d34-0410-b5e6-96231b3b80d8
16 files changed