TestCPP11EnumTypes.py should have covered all our bases when it comes
to typed enums, but it missed the regression introduced in r374066.
The reason it didn't catch it is somewhat funny: the test was copied
over from another test that recompiled a source file with a different
base type every time, but neither the test source nor the python code
was adapted for testing enums. As a result, this test was just running
8 times the exact same checks on the exact same binary.
This commit fixes the coverage and addresses the issue revealed by
the new tests.
llvm-svn: 374108