[turbofan] Move SimplifiedOperatorBuilder into JSGraph.

test/unittests/compiler/js-context-relaxation-unittest.cc

Index: test/unittests/compiler/js-context-relaxation-unittest.cc
diff --git a/test/unittests/compiler/js-context-relaxation-unittest.cc b/test/unittests/compiler/js-context-relaxation-unittest.cc
index 98612a218fb98a0daa9bb38a6c10277b3bc5ed53..12ca1212e087de0919166c97f31d351ab36c97c6 100644
--- a/test/unittests/compiler/js-context-relaxation-unittest.cc
+++ b/test/unittests/compiler/js-context-relaxation-unittest.cc
@@ -20,7 +20,8 @@ class JSContextRelaxationTest : public GraphTest {
   Reduction Reduce(Node* node, MachineOperatorBuilder::Flags flags =
                                    MachineOperatorBuilder::kNoFlags) {
     MachineOperatorBuilder machine(zone(), kMachPtr, flags);
-    JSGraph jsgraph(isolate(), graph(), common(), javascript(), &machine);
+    JSGraph jsgraph(isolate(), graph(), common(), javascript(), nullptr,
+                    &machine);
     // TODO(titzer): mock the GraphReducer here for better unit testing.
     GraphReducer graph_reducer(zone(), graph());
     JSContextRelaxation reducer;
@@ -29,7 +30,8 @@ class JSContextRelaxationTest : public GraphTest {
 
   Node* EmptyFrameState() {
     MachineOperatorBuilder machine(zone());
-    JSGraph jsgraph(isolate(), graph(), common(), javascript(), &machine);
+    JSGraph jsgraph(isolate(), graph(), common(), javascript(), nullptr,
+                    &machine);
     return jsgraph.EmptyFrameState();
   }