[Driver] Fix multiple bugs related to dependency file options: -M -MM -MD -MMD -MT -MQ

-M -o test.i => dependency file is test.d, not test.i
-MM -o test.i => dependency file is test.d, not test.i
-M -MMD => bogus warning -Wunused-command-line-argument
-M MT dummy => -w not rendered

llvm-svn: 371918