We were still using the Unix response file tokenizer for all driver
modes. This was difficult to get right in the beginning because there is
a circular dependency. The Driver class also can't officially determine
its mode until it can see all possible --driver-mode= flags, and those
flags could come from the response file.
Now we use the Windows parsing algorithm if the program name looks like
clang-cl, or if the --driver-mode=cl flag is present on the main command
line.
Fixes PR23709.
Reviewers: hans
Differential Revision: http://reviews.llvm.org/D11229
llvm-svn: 242346