RFR [12] 8212001: Verify exported symbols in java.base (libjava)

[Pavel Rappo]

Hello,

Please review the following change:

 http://cr.openjdk.java.net/~prappo/8212001/webrev.00

This is yet another clean-up kind of change. It seals unnecessarily exported
functions. This time from libjava. Also couldn't help fixing a typo. Not only
does it soothe aesthetic discomfort, it also helps with search (including
correct indexing). This change has been built and tested on all supported
platforms.

A note for reviewers. I noticed an asymmetry in the following declarations[^1]:

  JNIEXPORT jint handleRead(FD fd, void *buf, jint len);
  JNIEXPORT jlong JNICALL handleLseek(FD fd, jlong offset, jint whence);

These functions seem to be used in exactly the same way (from libzip). Is there
any reason for this difference (JNICALL)?

[^1]: http://cr.openjdk.java.net/~prappo/8212001/webrev.00/src/java.base/windows/native/libjava/io_util_md.h.html (lines 48, 52 and 53)