Disable parallel + fusion again as there is another bug in it -> scf pass preventing it from working

Author: pthomadakis

lib/Dialect/IndexTree/Transforms/KernelFusion.cpp

@@ -833,6 +833,11 @@ void fuseITrees(IndexTreeOp new_itree,
   indexTree::YieldOp yield_op = llvm::cast<indexTree::YieldOp>(new_itree.getRegion().getBlocks().front().getTerminator());
   OpBuilder::InsertionGuard guard(rewriter);
   rewriter.setInsertionPoint(yield_op);
+  /// TODO: Parallel execution does not seem to work properly when fusion is in place...
+  for(auto indexOp : host_index_ops)
+  {
+    indexOp.setIsParallel(false);
+  }
   /// Fuse each other itree to the new itree.
   for (uint32_t tree_i = 1; tree_i < num_itrees; ++tree_i) {
     /// Create Index Ops: 1) Record the common index ops, then 2) add the new index ops.