[m-dev.] for review: bug fix for RL query optimization

[Simon Taylor]

> > compiler/rl_block_opt.m:
> > 	Fix a bug where multiple copies of the output of a projection
> > 	were being created.
> 
> That looks fine.  But a regression test might be a good idea.

This is a performance bug, so a regression test isn't really possible.
I'll change the log message to make that clear.

> Currently we don't have any test cases for Aditi in the Mercury
> test suite.  Do you have a test suite for Aditi?

I've got some test cases which I'll add to the test suite soon.

Simon.