The linker wrapper is used to perform linking and wrapping of embedded
device object files. Currently its internals are not able to be tested
easily. This patch adds the `--dry-run` and `--print-wrapped-module`
options to investigate the link jobs that will be run along with the
wrapped code that will be created to register the binaries.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D124039
Joseph Huber