using bsr even with no popcnt present (#852)

src/sha1_hash.cpp

@@ -76,8 +76,6 @@ namespace libtorrent
 			}
 
 #if TORRENT_HAS_SSE
-			if (aux::mmx_support)
-			{
 #ifdef __GNUC__
 			return ret + __builtin_clz(v);
 #else
@@ -85,7 +83,6 @@ namespace libtorrent
 			_BitScanReverse(&pos, v);
 			return ret + 31 - pos;
 #endif
-			}
 #else
 			// http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious
 			static const int MultiplyDeBruijnBitPosition[32] =