Revert "added -Xswiftc flag before -I"
Revert "added -Xswiftc flag before -I"

This reverts commit eaa05a23ea3cb08ac6ec9b4e2740edebeb1b4976.

IBM-Swift/Kitura-net,IBM-Swift/Kitura-net,IBM-Swift/Kitura-net,IBM-Swift/Kitura-net,naithar/Kitura-net