[clang-scan-deps] Expand response files before the argument adjuster (#89950)

Previously, since response (.rsp) files weren't expanded at the very
beginning of clang-scan-deps, we only parsed the command-line as
provided in the Clang .cdb file. Unfortunately, when using Unreal
Engine, arguments are always generated in a .rsp file (ie.
`/path/to/clang-cl.exe @/path/to/filename_args.rsp`).

After this patch, `/Fo` can be parsed and added to the final
command-line. Without this option, the make targets that are emitted are
made up from the input file name alone. We have some cases where the
same input in the project generates several output files, so we end up
with duplicate make targets in the scan-deps emitted dependency file.

0 files changed, 0 insertions, 0 deletions