There is another
thread on Sun's forums that at least talks about what ir.out is and some past problems (maybe re-occuring in the version of the compiler you are using).
Quote:
When you compile with optimization, the file ir.out is created by the compiler front end (parser) and used by the optimizer and code generator. The file is automatically deleted at the end of the compilation.
The file is created in the directory used for temporary files, normally /tmp. (Refer to the compiler docs for instructions on how you can use a different location.) The "can't open ir.out" message normally occurs when you don't have write permission in the directory used for temp files, or when the file system is full.
If the above doesn't help, have you opened a support call? Although intelligence is a random finding in all support groups, you never know what you'll find.
Cheers,
Keith