Update to NSPR 4.10.2.

nspr/pr/include/prbit.h

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef prbit_h___
 #define prbit_h___
 
 #include "prtypes.h"
 PR_BEGIN_EXTERN_C
 
-/* replace compare/jump/add/shift sequence with x86 BSF/BSR instruction */
-#if defined(_WIN32) && (_MSC_VER >= 1300) && (defined(_M_IX86) || defined(_M_AMD64))
+/*
+** Replace compare/jump/add/shift sequence with compiler built-in/intrinsic
+** functions.
+*/
+#if defined(_WIN32) && (_MSC_VER >= 1300) && \
+    (defined(_M_IX86) || defined(_M_AMD64) || defined(_M_ARM))
   unsigned char _BitScanForward(unsigned long * Index, unsigned long Mask);
   unsigned char _BitScanReverse(unsigned long * Index, unsigned long Mask);
 # pragma  intrinsic(_BitScanForward,_BitScanReverse)
   __forceinline static int __prBitScanForward32(unsigned int val)
   { 
     unsigned long idx;
     _BitScanForward(&idx, (unsigned long)val);
     return( (int)idx );
   }
   __forceinline static int __prBitScanReverse32(unsigned int val)
@@ skipping 102 matching lines @@
 ** (a << 4) | (a >> 28) is frequently used instead. Most compilers convert
 ** this to a rotate instruction, but MSVC doesn't without a little help.
 ** To get MSVC to generate a rotate instruction, we have to use the _rotl
 ** or _rotr intrinsic and use a pragma to make it inline.
 **
 ** Note: MSVC in VS2005 will do an inline rotate instruction on the above
 ** construct.
 */
 
 #if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_AMD64) || \
-    defined(_M_X64))
+    defined(_M_X64) || defined(_M_ARM))
 #include <stdlib.h>
 #pragma intrinsic(_rotl, _rotr)
 #define PR_ROTATE_LEFT32(a, bits) _rotl(a, bits)
 #define PR_ROTATE_RIGHT32(a, bits) _rotr(a, bits)
 #else
 #define PR_ROTATE_LEFT32(a, bits) (((a) << (bits)) | ((a) >> (32 - (bits))))
 #define PR_ROTATE_RIGHT32(a, bits) (((a) >> (bits)) | ((a) << (32 - (bits))))
 #endif
 
 PR_END_EXTERN_C
 #endif /* prbit_h___ */