RFR : 8217093: Support extended-length paths in parse_manifest.c on windows

[Baesken, Matthias]

Hello,  please review this small  adjustment to  parse_manifest.c  .
It adds support  for extended - length paths  (on Window)  .

(see   https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file#maximum-path-length-limitation
For  extended length paths )

Additionally ,  some small memory leaks   are fixed in  find_file .

Bug/webrev :

https://bugs.openjdk.java.net/browse/JDK-8217093

http://cr.openjdk.java.net/~mbaesken/webrevs/8217093.0/


Best rergards, Matthias