[ast] Add an asserts only option that causes the AST printer to print out an increasing ID for all suppressed statements.

I am using this to better test out suppression statements. I am finding that
FileCheck runs into issues with some of the '#if' lines I am trying to match. I
am able to use this option with my asserts only test to uniquely identify a '#if
...' statement and thus have the pattern matching work. I needed this to get the
test in the next commit to pass testing.

Author: gottesmm

lib/AST/ASTPrinter.cpp

@@ -62,6 +62,7 @@
 #include "clang/Lex/MacroInfo.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/SaveAndRestore.h"
@@ -71,6 +72,15 @@
 
 using namespace swift;
 
+#ifndef NDEBUG
+static llvm::cl::opt<bool> NumberSuppressionChecks(
+    "swift-ast-printer-number-suppression-checks",
+    llvm::cl::desc("Used to number suppression checks in swift interface files "
+                   "to make it easier to FileCheck them. Only available with "
+                   "asserts enabled and intended for compiler tests."),
+    llvm::cl::init(false), llvm::cl::Hidden);
+#endif
+
 // Defined here to avoid repeatedly paying the price of template instantiation.
 const std::function<bool(const ExtensionDecl *)>
     PrintOptions::defaultPrintExtensionContentAsMembers
@@ -3199,6 +3209,15 @@ static void printCompatibilityCheckIf(ASTPrinter &printer, bool isElseIf,
     }
     printer << "$" << getFeatureName(feature);
   }
+
+#ifndef NDEBUG
+  if (NumberSuppressionChecks) {
+    static unsigned totalSuppressionChecks = 0;
+    printer << " // Suppression Count: " << totalSuppressionChecks;
+    ++totalSuppressionChecks;
+  }
+#endif
+
   printer.printNewline();
 }
 

test/Concurrency/sending_conditional_suppression.swift

@@ -1,6 +1,8 @@
 // RUN: %empty-directory(%t)
 
-// RUN: %target-swift-frontend -enable-upcoming-feature SendingArgsAndResults -swift-version 5 -enable-library-evolution -module-name test -emit-module -o %t/test.swiftmodule -emit-module-interface-path - %s | %FileCheck %s
+// RUN: %target-swift-frontend -enable-upcoming-feature SendingArgsAndResults -swift-version 5 -enable-library-evolution -module-name test -emit-module -o %t/test.swiftmodule -emit-module-interface-path - -disable-availability-checking -swift-ast-printer-number-suppression-checks %s | %FileCheck %s
+
+// REQUIRES: asserts
 
 public class NonSendableKlass {}