RFR: JDK-8188185 Windows build fails in configure after fix for JDK-8188136

[Tim Bell]

Bug report:

https://bugs.openjdk.java.net/browse/JDK-8188185

Webrev:

http://cr.openjdk.java.net/~tbell/8188185

Please review this update to back out the change done in bin/jib.sh
under 8188136:

-# Provide a reasonable default for the --src-dir parameter if run out 
of tree
-if [ -z "${JIB_SRC_DIR}" ]; then
-    export JIB_SRC_DIR="${mydir}/../"
-fi
-

8188136 enabled out of tree builds (where the build destination
directory is not located in the source tree).  Unfortunately this
broke the default (in tree) builds on Windows platforms, affecting many
internal users.

Thank you-

Tim