Fuzzer action: surround loop-safe statements in arbitrary well-behaved loop

[MattWindsor91]

Once we have #211, we can do things like inserting:

int i = 0;

for (i = 0; i < 4 /* random small positive int */; i++) {
  // loop-safe statements here
}

This would also serve as a very good way to find fuzzer actions that are not loop-safe :D

[MattWindsor91]

This is done, but needs some tweaking as it seems to keep triggering run timeouts.