Only print registered targets for `--version`
Only print registered targets for `--version`

Summary:
In D33900, I added printing of the registered targets in clang's
`PrintVersion` function, which is not only used for `--version` output,
but also for `-v` (verbose mode) and `-###`.  Especially the latter
seems to trip up some test cases, so it is probably better to only print
the registered targets for `--version`.

Reviewers: nemanjai, mehdi_amini

Reviewed By: nemanjai

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33981

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@304899 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang