I add my voice to this: the should be a way to inline functions and method calls.

Granted you can use the pre-processor (perl -P) to inline functions but this does not work for method calls. This is really bad when designing OO Perl, where I find myself using straight hash access ($o->{field}) instead of accessors ($o->field) for some often-called methods (or writing painfull and risky kludges), which makes maintenance much harder

I am actually very surprised this is not even a Perl 6 RFC, I would think that this is a simple (I would think it is quite easy to implement) way to enhance speed or maintainability of OO Perl programs.