ScalarSafeChars array in Output::scalarString (See YAMLTraits.cpp line 554 as
of r196428), this test will fail: The path will be single quoted to preserve
the 'unsafe' characters, which doesn't match the expected (unquoted) output.
Notionally "unsafe" characters include fairly innocuous ones like the '+'
symbol (I don't know enough YAML to be sure, but I suspect '+' doesn't really
need to be quoted).

I have added some sed lines to strip leading spaces, and leading and trailing
single quote (') characters from the path. That should make this test slightly
more robust.

If possible, this test should be rewritten to use FileCheck, rather than
diffing against expected output - the latter is likely to brittle, and require
further sed goop in the future.

llvm-svn: 196439