[turbofan] Split pure nodes in the scheduler if beneficial.

src/compiler/common-operator.cc

Index: src/compiler/common-operator.cc
diff --git a/src/compiler/common-operator.cc b/src/compiler/common-operator.cc
index b9aadefdae80a8e18c7f177a797d540c619f30a0..d6e5acd3c0caf5db92d257686ca616fda1216c9f 100644
--- a/src/compiler/common-operator.cc
+++ b/src/compiler/common-operator.cc
@@ -487,11 +487,12 @@ const Operator* CommonOperatorBuilder::Call(const CallDescriptor* descriptor) {
 
 
 const Operator* CommonOperatorBuilder::Projection(size_t index) {
-  return new (zone()) Operator1<size_t>(       // --
-      IrOpcode::kProjection, Operator::kPure,  // opcode
-      "Projection",                            // name
-      1, 0, 0, 1, 0, 0,                        // counts
-      index);                                  // parameter
+  return new (zone()) Operator1<size_t>(         // --
+      IrOpcode::kProjection,                     // opcode
+      Operator::kFoldable | Operator::kNoThrow,  // flags
+      "Projection",                              // name
+      1, 0, 0, 1, 0, 0,                          // counts
+      index);                                    // parameter
 }