RFR 8060432: tools/pack200/TestNormal.java fails on Windows with java.io.FileNotFoundException after JDK-8058854

[Amy Lu]

Please review the test fix.

bug: https://bugs.openjdk.java.net/browse/JDK-8060432
webrev: http://cr.openjdk.java.net/~weijun/8060432/webrev.00/

This test is to test
compareJars(new JarFile("normalized.jar"), new JarFile("repacked.jar"));
where the jar files (normalized.jar repacked.jar and original.jar) are 
created by "jar cnf" "jar cf" or "pack200 -r”.

extractJar(JarFile jf, File where) is not really needed as this method 
just try to provide some files for the test to do "jar cnf”. Actually, 
"jar cnf" can work on any files, test just need some files to jar with.

Test can just simply created some files for that purpose.

Thanks,
Amy