Compiling and running a simple GC

[darleybarreto]

A while ago I've found a simple gc to use on a simple LISP implementation to be compiled with ppci-cc. What is lacking on master is __builtin_frame_address(0) and set/longjmp. Do you think this gc would be an interesting example to place inside tools? I have fixes for these two (x86_64). Instead of using a builtin __builtin_frame_address, I've made changes in the inline asm to allow something like this:

long ret;
asm("mov %0, rbp": "=r"(ret) ::);
void *tos = (void*) ret;