[wasm] Enforce that function bodies end with the \"end\" opcode.

test/mjsunit/wasm/indirect-tables.js

Index: test/mjsunit/wasm/indirect-tables.js
diff --git a/test/mjsunit/wasm/indirect-tables.js b/test/mjsunit/wasm/indirect-tables.js
index 2ccc4a5d1831f6ff36ae6d4f250a754e1020171a..057d0f3661f044879a28dc6015484182a8ee1f19 100644
--- a/test/mjsunit/wasm/indirect-tables.js
+++ b/test/mjsunit/wasm/indirect-tables.js
@@ -443,7 +443,7 @@ function js_div(a, b) { return (a / b) | 0; }
   }
 
   let new_builder = new WasmModuleBuilder();
-  new_builder.addExport("wasm", new_builder.addFunction("", kSig_v_v));
+  new_builder.addExport("wasm", new_builder.addFunction("", kSig_v_v).addBody([]));
   new_builder.addImportedTable("x", "table", 20, 30);
   let new_module = new WebAssembly.Module(new_builder.toBuffer());
   let instance = new WebAssembly.Instance(new_module, {x: {table: table}});