Revert "Driver: Don't mix system tools with devtoolset tools on RHEL"
Revert "Driver: Don't mix system tools with devtoolset tools on RHEL"

This reverts commit r304293.

This was comitted accidentally.

git-svn-id: 42672b9bb47426b7a676b2951937ee8d5bc5f62c@304296 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang