wip - fix #636, check memory before calculating offset

crates/jit/src/compiler.rs

@@ -163,8 +163,9 @@ impl Compiler {
                 let body_len = compilation.get(i).body.len();
                 funcs.push((ptr, body_len));
             }
-            let module_vmctx_info = {
             let ofs = VMOffsets::new(target_config.pointer_bytes(), &module);
+            if ofs.num_defined_memories > 0 {
+                let module_vmctx_info = {
                     let memory_offset =
                         ofs.vmctx_vmmemory_definition_base(DefinedMemoryIndex::new(0)) as i64;
                     ModuleVmctxInfo {
@@ -185,6 +186,9 @@ impl Compiler {
                 Some(bytes)
             } else {
                 None
+            }
+        } else {
+            None
         };
 
         let jt_offsets = compilation.get_jt_offsets();