__wine_dbg_output accumulates the output characters in a debug_info
structure, flushing it when it encounters '\n'. If debug_info plus the
new string exceed 1024 characters, append_output will print

> wine_dbg_output: debugstr buffer overflow

and then crash the process via abort().

wine_dbgstr_variant limits the length printed for any individual argument,
but a function with multiple parameters can still plausibly exceed 1024.

Fixed by formatting the TRACE for each argument on a separate line,
as similar places (like oleaut32/typelib.c:dump_DispParms) do.