Revert "Re-land: Add new hidden option -print-changed which only reports changes to IR"

The test added in this commit is failing on Windows bots:

http://lab.llvm.org:8011/builders/llvm-clang-win-x-armv7l/builds/1269

This reverts commit f9e6d1e and follow-up commit 6859d95.

Author: dyung

llvm/include/llvm/Passes/StandardInstrumentations.h

@@ -124,97 +124,6 @@ class PreservedCFGCheckerInstrumentation {
   void registerCallbacks(PassInstrumentationCallbacks &PIC);
 };
 
-// Base class for classes that report changes to the IR.
-// It presents an interface for such classes and provides calls
-// on various events as the new pass manager transforms the IR.
-// It also provides filtering of information based on hidden options
-// specifying which functions are interesting.
-// Calls are made for the following events/queries:
-// 1.  The initial IR processed.
-// 2.  To get the representation of the IR (of type \p T).
-// 3.  When a pass does not change the IR.
-// 4.  When a pass changes the IR (given both before and after representations
-//         of type \p T).
-// 5.  When an IR is invalidated.
-// 6.  When a pass is run on an IR that is not interesting (based on options).
-// 7.  When a pass is ignored (pass manager or adapter pass).
-// 8.  To compare two IR representations (of type \p T).
-template <typename IRUnitT> class ChangePrinter {
-protected:
-  ChangePrinter() : InitialIR(true) {}
-
-public:
-  virtual ~ChangePrinter();
-
-  // Determine if this pass/IR is interesting and if so, save the IR
-  // otherwise it is left on the stack without data
-  void saveIRBeforePass(Any IR, StringRef PassID);
-  // Compare the IR from before the pass after the pass.
-  void handleIRAfterPass(Any IR, StringRef PassID);
-  // Handle the situation where a pass is invalidated.
-  void handleInvalidatedPass(StringRef PassID);
-
-protected:
-  // called on the first IR processed
-  virtual void handleInitialIR(Any IR) = 0;
-  // called before and after a pass to get the representation of the IR
-  virtual void generateIRRepresentation(Any IR, StringRef PassID,
-                                        IRUnitT &Output) = 0;
-  // called when the pass is not iteresting
-  virtual void omitAfter(StringRef PassID, std::string &Name) = 0;
-  // called when an interesting IR has changed
-  virtual void handleAfter(StringRef PassID, std::string &Name,
-                           const IRUnitT &Before, const IRUnitT &After,
-                           Any) = 0;
-  // called when an interesting pass is invalidated
-  virtual void handleInvalidated(StringRef PassID) = 0;
-  // called when the IR or pass is not interesting
-  virtual void handleFiltered(StringRef PassID, std::string &Name) = 0;
-  // called when an ignored pass is encountered
-  virtual void handleIgnored(StringRef PassID, std::string &Name) = 0;
-  // called to compare the before and after representations of the IR
-  virtual bool same(const IRUnitT &Before, const IRUnitT &After) = 0;
-
-  // stack of IRs before passes
-  std::vector<IRUnitT> BeforeStack;
-  // Is this the first IR seen?
-  bool InitialIR;
-};
-
-// A change printer based on the string representation of the IR as created
-// by unwrapAndPrint.  The string representation is stored in a std::string
-// to preserve it as the IR changes in each pass.  Note that the banner is
-// included in this representation but it is massaged before reporting.
-class IRChangePrinter : public ChangePrinter<std::string> {
-public:
-  IRChangePrinter();
-  ~IRChangePrinter() override;
-  void registerCallbacks(PassInstrumentationCallbacks &PIC);
-
-protected:
-  // called on the first IR processed
-  void handleInitialIR(Any IR) override;
-  // called before and after a pass to get the representation of the IR
-  void generateIRRepresentation(Any IR, StringRef PassID,
-                                std::string &Output) override;
-  // called when the pass is not iteresting
-  void omitAfter(StringRef PassID, std::string &Name) override;
-  // called when an interesting IR has changed
-  void handleAfter(StringRef PassID, std::string &Name,
-                   const std::string &Before, const std::string &After,
-                   Any) override;
-  // called when an interesting pass is invalidated
-  void handleInvalidated(StringRef PassID) override;
-  // called when the IR or pass is not interesting
-  void handleFiltered(StringRef PassID, std::string &Name) override;
-  // called when an ignored pass is encountered
-  void handleIgnored(StringRef PassID, std::string &Name) override;
-  // called to compare the before and after representations of the IR
-  bool same(const std::string &Before, const std::string &After) override;
-
-  raw_ostream &Out;
-};
-
 /// This class provides an interface to register all the standard pass
 /// instrumentations and manages their state (if any).
 class StandardInstrumentations {
@@ -223,7 +132,6 @@ class StandardInstrumentations {
   TimePassesHandler TimePasses;
   OptNoneInstrumentation OptNone;
   PreservedCFGCheckerInstrumentation PreservedCFGChecker;
-  IRChangePrinter PrintChangedIR;
 
 public:
   StandardInstrumentations(bool DebugLogging) : PrintPass(DebugLogging) {}

llvm/lib/IR/LegacyPassManager.cpp

@@ -87,14 +87,14 @@ static cl::opt<bool> PrintAfterAll("print-after-all",
 static cl::opt<bool>
     PrintModuleScope("print-module-scope",
                      cl::desc("When printing IR for print-[before|after]{-all} "
-                              "and change reporters always print a module IR"),
+                              "always print a module IR"),
                      cl::init(false), cl::Hidden);
 
 static cl::list<std::string>
     PrintFuncsList("filter-print-funcs", cl::value_desc("function names"),
                    cl::desc("Only print IR for functions whose name "
                             "match this for all print-[before|after][-all] "
-                            "and change reporter options"),
+                            "options"),
                    cl::CommaSeparated, cl::Hidden);
 
 /// This is a helper to determine whether to print IR before or