While looking into the Emacs garbage collector's stack-overflow problems 
I noticed several opportunities for improving performance and 
simplifying the code in minor ways. I plan to install the attached 
patches to take advantage of these opportunities; although they don't 
address stack overflow, they can be thought of as a first, cleanup step 
toward addressing stack overflow.

Overall these patches trim about 250 lines from the C source code, and 
should improve efficiency by not creating objects on the heap to handle 
stack-related events such as implementing save-excursion. This patch 
also removes primitives like 'free_misc' that ask for trouble by 
second-guessing the garbage collector. I'm filing this as a bug report 
in order to give the patches a bit of time to cool before installing. 
Comments welcome, as usual.