Summary:
This is http://llvm.org/PR15802. Backslashes preceding double quotes in
arguments must be escaped. The interesting bit is that all other
backslashes should *not* be escaped, because the un-escaping logic is
only triggered by the presence of a double quote character.
Reviewers: Bigcheese
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D705
llvm-svn: 180035
