[tclquadcode] NRE with expansion

[Donal K. F. <don...@ma...>]

Ah, the benefits of an intercontinental flight!

NRE now compiles and works with expansion (once I sync my fossil repo). 
It was fiddly, but was essentially just a blend of what existed under 
the *assumption* that by the time we hit this code, we're basically 
giving up on compiling deep inside. Theoretically, we might be able to 
do better with the case where the initial word is not expanded… but I 
don't check that.

It assumes that arguments needing expansion are always well-formed 
lists. I can't remember if we check that elsewhere. :-)

Donal.