makeSpecializationSet: do not assume parameters have a fixed position

Additionally, do not require the user to add the parameters
to the space first.  Trying to check if a parameter already
appears in a space currently requires functionality that
is only available in the TC copy of isl, which is what this commit
is trying to remove.  Simply adding the parameter if it does not
already appear is much easier.

Author: Sven Verdoolaege

include/tc/external/detail/islpp.h

@@ -317,37 +317,24 @@ inline isl::set makeParameterContext(
 
 // Given a space and values for parameters, this function creates the set
 // that ties the space parameter to the values.
-// This assumes space.dim(isl::dim_type::param) == paramValues.size()
 //
 template <typename T>
 inline isl::set makeSpecializationSet(
     isl::space space,
-    const std::unordered_map<int, T>& paramValues) {
-  CHECK_GE(space.dim(isl::dim_type::param), paramValues.size());
-  auto lspace = isl::local_space(space);
+    const std::unordered_map<std::string, T>& paramValues) {
+  auto ctx = space.get_ctx();
+  for (auto kvp : paramValues) {
+    space = space.add_param(isl::id(ctx, kvp.first));
+  }
   auto set = isl::set::universe(space);
   for (auto kvp : paramValues) {
-    auto affParam = isl::aff(lspace, isl::dim_type::param, kvp.first);
+    auto id = isl::id(ctx, kvp.first);
+    isl::aff affParam(isl::aff::param_on_domain_space(space, id));
     set = set & (isl::aff_set(affParam) == kvp.second);
   }
   return set;
 }
 
-template <typename T>
-inline isl::set makeSpecializationSet(
-    isl::space space,
-    const std::unordered_map<std::string, T>& paramValues) {
-  CHECK_GE(space.dim(isl::dim_type::param), paramValues.size());
-  std::unordered_map<int, T> aux;
-  for (auto kvp : paramValues) {
-    auto pos = space.find_dim_by_name(isl::dim_type::param, kvp.first);
-    CHECK_LE(0, pos) << "No " << kvp.first << " in: " << space;
-    CHECK_EQ(0, aux.count(pos));
-    aux[pos] = kvp.second;
-  }
-  return makeSpecializationSet(space, aux);
-}
-
 template <typename T>
 inline isl::set makeSpecializationSet(
     isl::space space,