YJIT: other_cb is None in tests

Since the other cb is in CodegenGlobals, and we want Rust tests to be
self-contained.

yjit/src/asm/mod.rs

@@ -139,6 +139,7 @@ impl CodeBlock {
         }
 
         // Move the other CodeBlock to the same page if it'S on the furthest page
+        #[cfg(not(test))]
         self.other_cb().unwrap().set_page(next_page_idx.unwrap(), &jmp_ptr);
 
         return !self.dropped_bytes;