[polly] In IslNodeBuilder::createMark() use isl::noexception bindings [NFC]

[refactormyself]

Summary

The C++ bindings in isl_noexception provide better pointer management.
This allows the use of convenient memory management tools in C++.

• Replace the isl C entities with isl_noexception bindings
• Refactor calls to this function

No functional changes were made.

[Meinersbur]

polly/lib/CodeGen/IslNodeBuilder.cpp

408

With the argument now being out smart pointer, we prefer using its accessor methods.

409

same here

polly/include/polly/CodeGen/IslNodeBuilder.h

protected:
 
   /// Generate code for a marker now.
   ///
   /// For mark nodes with an unknown name, we just forward the code generation
   /// to its child. This is currently the only behavior implemented, as there is
   /// currently not special handling for marker nodes implemented.
   ///
   /// @param Mark The node we generate code for.
-  virtual void createMark(__isl_take isl_ast_node *Marker);
+  virtual void createMark(isl::ast_node Marker);
 
   virtual void createFor(__isl_take isl_ast_node *For);
 
   /// Set to remember materialized invariant loads.
   ///
   /// An invariant load is identified by its pointer (the SCEV) and its type.
   SmallSet<std::pair<const SCEV *, Type *>, 16> PreloadedPtrs;
 

polly/lib/CodeGen/IslNodeBuilder.cpp

void IslNodeBuilder::createUserVector(__isl_take isl_ast_node *User,
   createSubstitutionsVector(Expr, Stmt, VLTS, IVS, IteratorID);
   VectorBlockGenerator::generate(BlockGen, *Stmt, VLTS, S, NewAccesses);
   isl_id_to_ast_expr_free(NewAccesses);
   isl_map_free(S);
   isl_id_free(Id);
   isl_ast_node_free(User);
 }
 
-void IslNodeBuilder::createMark(__isl_take isl_ast_node *Node) {
-  auto *Id = isl_ast_node_mark_get_id(Node);
-  auto Child = isl_ast_node_mark_get_node(Node);
-  isl_ast_node_free(Node);
+void IslNodeBuilder::createMark(isl::ast_node Node) {
+  auto *Id = isl_ast_node_mark_get_id(Node.get());
+  auto *Child = isl_ast_node_mark_get_node(Node.get());
+
   // If a child node of a 'SIMD mark' is a loop that has a single iteration,
   // it will be optimized away and we should skip it.
   if (strcmp(isl_id_get_name(Id), "SIMD") == 0 &&
       isl_ast_node_get_type(Child) == isl_ast_node_for) {
     bool Vector = PollyVectorizerChoice == VECTORIZER_POLLY;
     int VectorWidth = getNumberOfIterations(isl::manage_copy(Child));
     if (Vector && 1 < VectorWidth && VectorWidth <= 16)
       createForVector(Child, VectorWidth);
void IslNodeBuilder::createBlock(__isl_take isl_ast_node *Block) {
   isl_ast_node_list_free(List);
 }
 
 void IslNodeBuilder::create(__isl_take isl_ast_node *Node) {
   switch (isl_ast_node_get_type(Node)) {
   case isl_ast_node_error:
     llvm_unreachable("code generation error");
   case isl_ast_node_mark:
-    createMark(Node);
+    createMark(isl::manage(Node));
     return;
   case isl_ast_node_for:
     createFor(Node);
     return;
   case isl_ast_node_if:
     createIf(Node);
     return;
   case isl_ast_node_user: