[Clang] Introduce Clang Linker Wrapper Tool

This patch introduces a linker wrapper tool that allows us to preprocess
files before they are sent to the linker. This adds a dummy action and
job to the driver stage that builds the linker command as usual and then
replaces the command line with the wrapper tool.

Depends on D116543

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D116544