Fix VC++ 2015 64-bit truncation warning in zlib

third_party/zlib/crc_folding.c

 /*
  * Compute the CRC32 using a parallelized folding approach with the PCLMULQDQ
  * instruction.
  *
  * A white paper describing this algorithm can be found at:
  * http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
  *
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  * Authors:
  *      Wajdi Feghali   <wajdi.k.feghali@intel.com>
@@ skipping 265 matching lines @@
     __m128i xmm_t0, xmm_t1, xmm_t2, xmm_t3;
 
     CRC_LOAD(s)
 
     if (len < 16) {
         if (len == 0)
             return;
         goto partial;
     }
 
-    algn_diff = 0 - (unsigned long)src & 0xF;
+    algn_diff = 0 - (uintptr_t)src & 0xF;
     if (algn_diff) {
         xmm_crc_part = _mm_loadu_si128((__m128i *)src);
         _mm_storeu_si128((__m128i *)dst, xmm_crc_part);
 
         dst += algn_diff;
         src += algn_diff;
         len -= algn_diff;
 
         partial_fold(s, algn_diff, &xmm_crc0, &xmm_crc1, &xmm_crc2, &xmm_crc3,
             &xmm_crc_part);
@@ skipping 187 matching lines @@
 
     xmm_crc2 = xmm_crc3;
     xmm_crc3 = _mm_clmulepi64_si128(xmm_crc3, crc_fold, 0x10);
     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc2);
     xmm_crc3 = _mm_xor_si128(xmm_crc3, xmm_crc1);
 
     crc = _mm_extract_epi32(xmm_crc3, 2);
     return ~crc;
     CRC_SAVE(s)
 }