[PATCH] Drop Cloog support

[Tobias Grosser]

Also, please add a symbolic link from checkout_cloog.sh to checkout_isl.sh.

This is hopefully enough to make the buildbots happy. After we updated zorg, we can drop this.

Otherwise we can commit this patch now. If there are fallouts, we can fix them as they appear.

Cheers,
Tobias

================
Comment at: utils/checkout_isl.sh:69
@@ -68,3 +65,1 @@
   # Remove the existing CLooG and ISL dirs to avoid crashing older git versions.
-  cd ${CLOOG_DIR}/..
-  run rmdir "${CLOOG_DIR}"
----------------
We need a cd ${ISL_DIR}/.. here. Otherwise, git complains of not being inside a valid working directory.

http://reviews.llvm.org/D6400