fix: Fix MSVC crash when using /Zi /Fddebug.pdb

fix: Fix MSVC crash when using /Zi /Fddebug.pdb

With /Zi, MSVC starts a long-lived mspdbsrv.exe background process. The
implementation of #1274 kills all processes created by ccache including
mspdbsrv.exe, which can make cl.exe crash with this error message:

    fatal error C1090: PDB API call failed, error code '23': (0x000006BA)

Fix this by setting JOB_OBJECT_LIMIT_SILENT_BREAKAWAY_OK to only kill
the compiler and not processes that the compiler creates.

Fixes #1386 in a better way.