Add __wbindgen_main to other backends

Author: daxpedda

crates/cli-support/src/js/mod.rs

@@ -414,6 +414,9 @@ impl<'a> Context<'a> {
 
                 if needs_manual_start {
                     footer.push_str("\nwasm.__wbindgen_start();\n");
+                    if self.start_found {
+                        footer.push_str("\nwasm.__wbindgen_main();\n");
+                    }
                 }
             }
 
@@ -428,6 +431,9 @@ impl<'a> Context<'a> {
 
                 if needs_manual_start {
                     footer.push_str("\nwasm.__wbindgen_start();\n");
+                    if self.start_found {
+                        footer.push_str("\nwasm.__wbindgen_main();\n");
+                    }
                 }
             }
 
@@ -461,7 +467,10 @@ impl<'a> Context<'a> {
                 }
 
                 if needs_manual_start {
-                    start = Some("\nwasm.__wbindgen_start();\n".to_string());
+                    let start = start.insert("\nwasm.__wbindgen_start();\n".to_string());
+                    if self.start_found {
+                        start.push_str("\nwasm.__wbindgen_main();\n");
+                    }
                 }
             }