Make TickBitmap.position internal (Uniswap#460)

Co-authored-by: Alice <[email protected]>

src/libraries/TickBitmap.sol

@@ -16,7 +16,7 @@ library TickBitmap {
     /// @param tick The tick for which to compute the position
     /// @return wordPos The key in the mapping containing the word in which the bit is stored
     /// @return bitPos The bit position in the word where the flag is stored
-    function position(int24 tick) private pure returns (int16 wordPos, uint8 bitPos) {
+    function position(int24 tick) internal pure returns (int16 wordPos, uint8 bitPos) {
         unchecked {
             wordPos = int16(tick >> 8);
             bitPos = uint8(int8(tick % 256));