Fix a default on covered switch found by -Wcovered-switch-default

Introduced in r178207

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@178212 91177308-0d34-0410-b5e6-96231b3b80d8
modularize - Fixed poor array usage.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@178214 91177308-0d34-0410-b5e6-96231b3b80d8
modularize - Updated futures comment.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@178216 91177308-0d34-0410-b5e6-96231b3b80d8