wasm_js_glue can be unicode, so make sure to convert to string properly. fixes regression from 78e2fcd (#4855)

Author: kripken

emcc.py

@@ -1697,7 +1697,7 @@ def save_intermediate(name=None, suffix='js'):
           wasm_js_glue = wasm_js_glue.replace('{{{ wasmJSMethod }}}', 'null')
         wasm_js_glue = wasm_js_glue.replace('{{{ WASM_BACKEND }}}', str(shared.Settings.WASM_BACKEND)) # if wasm backend, wasm contains memory segments
         wasm_js_glue += '\nintegrateWasmJS(Module);\n' # add a call
-        post_module += wasm_js_glue # we can set up the glue once we have the module
+        post_module += str(wasm_js_glue) # we can set up the glue once we have the module
 
       # Apply pre and postjs files
       if pre_js or post_module or post_js: