RFC: __FUNCTION__ and __PRETTY_FUNCTION__

[Neil Booth]

As Andreas pointed out, my string concatenation patches break the
concatenation of these functions.  They are documented as undergoing
concatenation.

However, g++ does _not_ concatenate these; it gives a parse error.
Only the C/ObjC front end concatenates them.  Until yesterday, anyway
8^)

I think their undergoing concatenation is wrong and a poor design
decision: it is a violation of strict ordering of the ISO C and C++
standards, since by the time we are compiling in phase 7, phase 6
string concatenation should already have been done.

So, since g++ does not concatenate these, and it makes moving string
concatenation out of the parser difficult, I would like to propose
changing the documentation to state that they do not concatenate.

Thoughts?

Neil.