Add extra gcc dependencies.

- not used until optional/conditional deps are implemented.

var/spack/packages/cloog/package.py

+from spack import *
+
+class Cloog(Package):
+    """CLooG is a free software and library to generate code for
+    scanning Z-polyhedra. That is, it finds a code (e.g. in C,
+    FORTRAN...) that reaches each integral point of one or more
+    parameterized polyhedra."""
+
+    homepage = "http://www.cloog.org"
+    url      = "http://www.bastoul.net/cloog/pages/download/count.php3?url=./cloog-0.18.1.tar.gz"
+    list_url = "http://www.bastoul.net/cloog/pages/download"
+
+    version('0.18.1', 'e34fca0540d840e5d0f6427e98c92252')
+    version('0.18.0', 'be78a47bd82523250eb3e91646db5b3d')
+    version('0.17.0', '0aa3302c81f65ca62c114e5264f8a802')
+
+    depends_on("gmp")
+    depends_on("isl")
+
+    def install(self, spec, prefix):
+        configure("--prefix=%s" % prefix,
+                  "--with-osl=no",
+                  "--with-isl=%s" % spec['isl'].prefix,
+                  "--with-gmp=%s" % spec['gmp'].prefix)
+        make()
+        make("install")

var/spack/packages/isl/package.py

+from spack import *
+
+class Isl(Package):
+    """isl is a thread-safe C library for manipulating sets and
+    relations of integer points bounded by affine constraints."""
+    homepage = "http://isl.gforge.inria.fr"
+    url      = "http://isl.gforge.inria.fr/isl-0.14.tar.bz2"
+
+    version('0.14', 'acd347243fca5609e3df37dba47fd0bb')
+
+    depends_on("gmp")
+
+    def install(self, spec, prefix):
+        configure("--prefix=%s" % prefix,
+                  "--with-gmp-prefix=%s" % spec['gmp'].prefix)
+        make()
+        make("install")

var/spack/packages/ppl/package.py

+from spack import *
+
+class Ppl(Package):
+    """The Parma Polyhedra Library (PPL) provides numerical
+    abstractions especially targeted at applications in the field of
+    analysis and verification of complex systems. These abstractions
+    include convex polyhedra, some special classes of polyhedra shapes
+    that offer interesting complexity/precision tradeoffs, and grids
+    which represent regularly spaced points that satisfy a set of
+    linear congruence relations. The library also supports finite
+    powersets and products of polyhedra and grids, a mixed integer
+    linear programming problem solver using an exact-arithmetic
+    version of the simplex algorithm, a parametric integer programming
+    solver, and primitives for termination analysis via the automatic
+    synthesis of linear ranking functions."""
+
+    homepage = "http://bugseng.com/products/ppl/"
+    url      = "http://bugseng.com/products/ppl/download/ftp/releases/1.1/ppl-1.1.tar.gz"
+
+    version('1.1', '4f2422c0ef3f409707af32108deb30a7')
+
+    depends_on("gmp")
+
+    def install(self, spec, prefix):
+        configure("--prefix=%s" % prefix,
+                  "--with-gmp=%s" % spec['gmp'].prefix)
+        make()
+        make("install")