Ribbit C RVM makes wrong assumptions on its GC

[chouettevan]

In multiple instances , the ribbit C RVM assumes the garbage collector does not run during a series of allocations,

Bug Trigger

apply the following patch to the C RVM:

diff --git a/src/host/c/rvm.c b/src/host/c/rvm.c
index ba2c4d4..2057952 100644
--- a/src/host/c/rvm.c
+++ b/src/host/c/rvm.c
@@ -591,9 +591,7 @@ void push2(obj car, obj tag) {
     gc();
   }
 #else
-  if (alloc == alloc_limit) {
     gc();
-  }
 #endif
 }

Compile virtually any scheme program (such as tests/00-ribbit/00-empty.scm)

Expected behaviour

Since ribbit is well built, the program executes normally

Actual behaviour.

A segfault due to parts of ribbit assuming the gc does not trigger on some allocation