Fixed enum printing for negative enums. There previously was no testing to...

Fixed enum printing for negative enums. There previously was no testing to validate that enum values were being displayed correctly.

Also added C++11 enum test cases to cover enums as int8_t, int16_t int32_t, int64_t, uint8_t, uint16_t, uint32_t, and uint64_t both for DWARF and dSYM cases. The DWARF being emitted by clang is missing the enum integer type, but the code is now ready to accept and deal with the integral type if it is supplied.

llvm-svn: 176548