[clang][IFS] Escape mangled names so MS ABI doesn't break YAML parsing.

Microsoft's ABI mangles names differently than Itanium and this breaks the LLVM
yaml parser unless the name is escaped in quotes. Quotes are being added to the
mangled names of the IFS file generation so that llvm-ifs doesn't break when
Windows triples are passed to the driver.

Differential Revision: https://reviews.llvm.org/D68915

llvm-svn: 374798