clang/test/Driver: Remove the feature "clang-driver" in three tests since they might work as expected since their first commit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188788 91177308-0d34-0410-b5e6-96231b3b80d8
clang/test/Driver: Remove the feature "clang-driver" since gcc-as has not been used with -integrated-as since r177360.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188789 91177308-0d34-0410-b5e6-96231b3b80d8
clang/test/Driver/cl-options.c: Remove the feature "clang-driver". It has been working since r188331.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188790 91177308-0d34-0410-b5e6-96231b3b80d8