[basic] Add an operator<<(llvm::raw_ostream &os, const SmallBitVector &) implementation.

For some reason LLVM doesn't provide this. I have written a few versions of this
in the Swift codebase. Makes sense to factor it out before I make another one.

Author: gottesmm

include/swift/Basic/SmallBitVector.h

@@ -0,0 +1,30 @@
+//===--- SmallBitVector.h -------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2022 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_BASIC_SMALLBITVECTOR_H
+#define SWIFT_BASIC_SMALLBITVECTOR_H
+
+#include "llvm/ADT/SmallBitVector.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+inline llvm::raw_ostream &operator<<(llvm::raw_ostream &os,
+                                     const SmallBitVector &bv) {
+  for (unsigned i = 0, e = bv.size(); i != e; ++i)
+    os << (bv[i] ? '1' : '0');
+  return os;
+}
+
+} // namespace llvm
+
+#endif

lib/SILOptimizer/Mandatory/MoveKillsCopyableAddressesChecker.cpp

@@ -141,6 +141,7 @@
 #include "swift/Basic/Defer.h"
 #include "swift/Basic/FrozenMultiMap.h"
 #include "swift/Basic/GraphNodeWorklist.h"
+#include "swift/Basic/SmallBitVector.h"
 #include "swift/SIL/BasicBlockBits.h"
 #include "swift/SIL/BasicBlockDatastructures.h"
 #include "swift/SIL/Consumption.h"
@@ -183,15 +184,6 @@ static void diagnose(ASTContext &Context, SourceLoc loc, Diag<T...> diag,
   Context.Diags.diagnose(loc, diag, std::forward<U>(args)...);
 }
 
-namespace llvm {
-llvm::raw_ostream &operator<<(llvm::raw_ostream &os, const SmallBitVector &bv) {
-  for (unsigned index : range(bv.size())) {
-    os << (bv[index] ? 1 : 0);
-  }
-  return os;
-}
-} // namespace llvm
-
 static SourceLoc getSourceLocFromValue(SILValue value) {
   if (auto *defInst = value->getDefiningInstruction())
     return defInst->getLoc().getSourceLoc();