[turbofan] Remove obsolete 'incomplete' flag from GraphDecorator.

src/compiler/source-position.cc

Index: src/compiler/source-position.cc
diff --git a/src/compiler/source-position.cc b/src/compiler/source-position.cc
index 93f89e03bc0c20c541b8537302fd387ac57904e5..48361ecac771d92a2899fae83dcc014b02002424 100644
--- a/src/compiler/source-position.cc
+++ b/src/compiler/source-position.cc
@@ -15,7 +15,7 @@ class SourcePositionTable::Decorator final : public GraphDecorator {
   explicit Decorator(SourcePositionTable* source_positions)
       : source_positions_(source_positions) {}
 
-  void Decorate(Node* node, bool incomplete) final {
+  void Decorate(Node* node) final {
     source_positions_->table_.Set(node, source_positions_->current_position_);
   }