Add a HasAccessMarkers flag to SILFunction.

This allows the verifier to be run before and after marker elimination.

include/swift/SIL/SILFunction.h

@@ -208,6 +208,10 @@ private:
   /// after the pass runs, we only see a semantic-arc world.
   bool HasQualifiedOwnership = true;
 
+  /// True if all memory access in this function is demarcated by well-formed
+  /// memory access markers.
+  bool HasAccessMarkers = false;
+
   SILFunction(SILModule &module, SILLinkage linkage, StringRef mangledName,
               CanSILFunctionType loweredType, GenericEnvironment *genericEnv,
               Optional<SILLocation> loc, IsBare_t isBareSILFunction,
@@ -320,6 +324,15 @@ public:
     HasQualifiedOwnership = false;
   }
 
+  /// Returns true if this function has well-formed access markers describing
+  /// all memory access.
+  bool hasAccessMarkers() const { return HasAccessMarkers; }
+
+  /// Sets the HasAccessMarkers flag to false.
+  void disableAccessMarkers() {
+    HasAccessMarkers = false;
+  }
+
   /// Returns the calling convention used by this entry point.
   SILFunctionTypeRepresentation getRepresentation() const {
     return getLoweredFunctionType()->getRepresentation();