http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60469
--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> --- You need to include gimple-expr.h header for that. But, if you look e.g. at c/c-typeck.c or c-family/cilk.c, it is already used in the FEs.
