Don't delete the module you're inspecting

Prior to this patch when you used `clang -module-file-info` clang would
delete the module on completion because the module was treated as an
output file.

This fixes the issue so you don't need to invoke cc1 directly to get
module file information.

Reviewed By: steven_wu, phosek

Differential Revision: https://reviews.llvm.org/D103547