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

src/compiler/instruction-selector.h

Index: src/compiler/instruction-selector.h
diff --git a/src/compiler/instruction-selector.h b/src/compiler/instruction-selector.h
index 767e19d0045e8a86050f49cf89be7179c7715173..81c0c15ee97a0fa7b48a7e3868ba79d2b189c5a1 100644
--- a/src/compiler/instruction-selector.h
+++ b/src/compiler/instruction-selector.h
@@ -33,10 +33,14 @@ class InstructionSelector final {
   // Forward declarations.
   class Features;
 
-  InstructionSelector(Zone* zone, size_t node_count, Linkage* linkage,
-                      InstructionSequence* sequence, Schedule* schedule,
-                      SourcePositionTable* source_positions,
-                      Features features = SupportedFeatures());
+  enum SourcePositionMode { kCallSourcePositions, kAllSourcePositions };
+
+  InstructionSelector(
+      Zone* zone, size_t node_count, Linkage* linkage,
+      InstructionSequence* sequence, Schedule* schedule,
+      SourcePositionTable* source_positions,
+      SourcePositionMode source_position_mode = kCallSourcePositions,
+      Features features = SupportedFeatures());
 
   // Visit code for the entire graph with the included schedule.
   void SelectInstructions();
@@ -219,6 +223,7 @@ class InstructionSelector final {
   Linkage* const linkage_;
   InstructionSequence* const sequence_;
   SourcePositionTable* const source_positions_;
+  SourcePositionMode const source_position_mode_;
   Features features_;
   Schedule* const schedule_;
   BasicBlock* current_block_;