[driver] Completely rework how superfluous options are stripped out of the crash

diagnostics script.

This addresses the FIXME pertaining to quoted arguments.  We also delineate
between those flags that have an argument (e.g., -D macro, -MF file) and
those that do not (e.g., -M, -MM, -MG).  Finally, we add the -dwarf-debug-flags
to the list of flags to be removed.
rdar://12329974

llvm-svn: 167152