bug#13274: Building emacs 24.2 fails if arguments to configure have the character " in them

[Jason Gross]

Line 2449 of emacs.c is
  Vsystem_configuration_options = build_string (EMACS_CONFIG_OPTIONS);
However, EMACS_CONFIG_OPTIONS is not a valid C string literal if I
pass, e.g., LDFLAGS="-Wl,-rpath
-Wl,\"/afs/csail.mit.edu/u/j/jgross/.local64/lib\"" to ./configure.
I'm not sure whether this is a failing of emac's configure script, or
of AC_DEFINE_UNQUOTED, which does not do anything special with "
characters.