JDK-8200178 changed the number of exported functions, on Windows in particular. These functions were exported explicitly from CoreLibraries.gmk:
ZIP_Open, ZIP_Close, ZIP_FindEntry, ZIP_ReadEntry, ZIP_GetNextEntry, ZIP_InflateFully, ZIP_CRC32 and ZIP_FreeEntry.

On Linux, in addition to the list above, the following functions were exported:
ZIP_GetEntry, ZIP_Lock, ZIP_Read, ZIP_Unlock.

Now these functions are also exported on Windows.

But, according to code in classLoader.cpp [1], these additional functions are not used and therefore can be hidden.

[1] http://hg.openjdk.java.net/jdk/jdk/file/e0af66d6e968/src/hotspot/share/classfile/classLoader.cpp#l1189