[Bug tree-optimization/86724] Compilation error with new isl 0.20 (missing includes)

[rainer.jung at kippdata dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86724

--- Comment #1 from Rainer Jung <rainer.jung at kippdata dot de> ---
For the sake of completeness, I think the following isl change removed the
implicit include chain that made the code work before isl 0.20:

http://repo.or.cz/isl.git/commitdiff/406f2e9e067adb901c45284c65bfdc32e29a1383

Before several already included isl header files included isl/local_space.h
which itself included the needed isl/space.h which in turn included the needed
isl/id.h. After the change, isl/local_space.h no longer includes space.h.