Update isl to remove platform dependent behavior

isl commit 9e01482 changed an internal comparision function to ensure
consistent results across different platforms. Differences that have
previously observed between Linux and Solaris 10 should disappear with
the updated isl version.
Update isl

isl commit f5ed5dd6 changed the output of one the test cases. We update
isl and the test case to allow CLooG to be compiled with this and later
versions of isl.
Another isl update that changes cloog's output
Update to isl 0.12

Signed-off-by: Tobias Grosser <tobias@grosser.es>
Fix error with automake 1.13+
Add isl and cloog-isl CMake modules (for CMake find_package function)

NB: the isl module is there for convenience purpose. If it appears
someday in isl itself, it should be removed.
Add osl extbody extension support
Fix include directory for libcloog-isl
Fix out of tree builds
Update to isl 0.12.1
CLooG 0.18.1

Signed-off-by: Tobias Grosser <tobias@grosser.es>
Added howto file for a new CLooG release
CLooG 0.18.2
Add a test_regenerate target for regenerating failing tests

"make test_regenerate" will update all failing tests with the
files generated by the current CLooG. Handy to update tests
that changed textually but remain semantically equivalent,
e.g., because of a polyhedral library update. Use with care!
Generate safety parentheses around compound expressions

Now CLooG generates statements with parentheses around expressions
with more than one term, e.g., S1(0,c1,(c2+c3)) instead of S1(0,c1,c2+c3).
The purpose of this change is to help users to avoid bugs when relying
on macros.
Loop execution time reporting

Set clast_for->time_var_name to the name of the variable which will
accumulate execution time of the body inside this loop (in seconds
double precision floating-point) if macro TIME is defined (-DTIME).
The code is linked to cloog_util_rtclock() that relies on gettimeofday
and is part of the CLooG library.

Signed-off-by: Uday Bondhugula <udayreddy@gmail.com>
Signed-off-by: Cedric Bastoul <cedric.bastoul@u-psud.fr>