save/restore file permission in modules writing/reading

[Mandy Chung]

The file permission of several files in the jdk is modified during the 
build.   Upon installing a module, I would expect that the modules 
writing/reading would restore the file permission.  

Currently, native cmds on all platforms and native libs on windows are 
assumed to have execute permission.  Would it be appropriate for the 
module file format to include the file permission info that can be 
saved/restored properly?

Mandy