file named dynimportfail. The _cgo_import.go file is only needed when
using internal linking mode, which is not the default when linking
programs that use cgo (as described below). If the linker sees a file
named dynimportfail it reports an error if it has been told to use
internal linking mode. This approach is taken because generating
_cgo_import.go requires doing a full C link of the package, which can