[turbofan] Don't spread global flag checks all over the compiler code.

test/unittests/compiler/instruction-selector-unittest.h

Index: test/unittests/compiler/instruction-selector-unittest.h
diff --git a/test/unittests/compiler/instruction-selector-unittest.h b/test/unittests/compiler/instruction-selector-unittest.h
index bbf382f67a0f31eb66dba21a8a412d7aeaebc2bd..a23d531a3aed142c87dc17979ec6565c3d9b8652 100644
--- a/test/unittests/compiler/instruction-selector-unittest.h
+++ b/test/unittests/compiler/instruction-selector-unittest.h
@@ -73,7 +73,9 @@ class InstructionSelectorTest : public TestWithContext,
       return Build(InstructionSelector::Features(), mode);
     }
     Stream Build(InstructionSelector::Features features,
-                 StreamBuilderMode mode = kTargetInstructions);
+                 StreamBuilderMode mode = kTargetInstructions,
+                 InstructionSelector::SourcePositionMode source_position_mode =
+                     InstructionSelector::kAllSourcePositions);
 
    private:
     MachineSignature* MakeMachineSignature(Zone* zone,