[region-isolation] Move the region isolation logging decls out of PartitionUtils.h -> RegionIsolation.h

These do not specifically have to do with PartitionUtils... they are really
logging options for the whole infrastructure, so it makes sense to have them in
the a different file.

lib/SILOptimizer/Utils/RegionIsolation.cpp

@@ -0,0 +1,36 @@
+//===--- RegionIsolation.cpp ----------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/SILOptimizer/Utils/RegionIsolation.h"
+
+#include "llvm/Support/CommandLine.h"
+
+using namespace swift;
+using namespace regionisolation;
+
+//===----------------------------------------------------------------------===//
+//                               MARK: Logging
+//===----------------------------------------------------------------------===//
+
+LoggingFlag swift::regionisolation::ENABLE_LOGGING;
+
+static llvm::cl::opt<LoggingFlag, true> // The parser
+    RegionBasedIsolationLog(
+        "sil-regionbasedisolation-log",
+        llvm::cl::desc("Enable logging for SIL region based isolation "
+                       "diagnostics"),
+        llvm::cl::Hidden,
+        llvm::cl::values(
+            clEnumValN(LoggingFlag::Off, "none", "no logging"),
+            clEnumValN(LoggingFlag::Normal, "on", "non verbose logging"),
+            clEnumValN(LoggingFlag::Verbose, "verbose", "verbose logging")),
+        llvm::cl::location(swift::regionisolation::ENABLE_LOGGING));