[bootstrap] Fix bootstrap script to pass '.a' files directly to swiftc.
[bootstrap] Fix bootstrap script to pass '.a' files directly to swiftc.

 - This should work, now that the autolink extraction knows how to crack open
   the .a and get the symbols from it.

vmanot/swift-package-manager,sschiau/swift-package-manager,abertelrud/swift-package-manager,mxcl/swift-package-manager,JGiola/swift-package-manager,mxcl/swift-package-manager,abertelrud/swift-package-manager,haskellswift/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,sschiau/swift-package-manager,rsmoz/swift-package-manager,abertelrud/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,vmanot/swift-package-manager,apple/swift-package-manager,JGiola/swift-package-manager,haskellswift/swift-package-manager,mxcl/swift-package-manager,mxcl/swift-package-manager,sschiau/swift-package-manager,haskellswift/swift-package-manager,abertelrud/swift-package-manager,haskellswift/swift-package-manager,apple/swift-package-manager,rsmoz/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,JGiola/swift-package-manager,vmanot/swift-package-manager,apple/swift-package-manager,sschiau/swift-package-manager