RSP file content is not copied into compile_commands.json while using Tasking compiler

[gerioldman]

https://github.com/ninja-build/ninja/blob/36843d387cb0621c1a288179af223d4f1410be73/src/ninja.cc#L885C3-L885C72

I am using the TASKING TriCore compiler with ninja, and after trying to generate compilation database with the option '-x', it still had the rsp files in it. I have referenced a code part which might be to blame, the TASKING compiler doesn't use the '@' syntax, but uses '--option-file=<filename>' or '-f <filename>' syntax.