add wasm.fallback module (#369)

This reverts commit c96e5cf50d.

emscripten/external-wasm.d.ts

@@ -1,7 +1,23 @@
 declare module 'external:emscripten/*.wasm' {
     /**
-     * This is a url relative from build output chunk.
+     * This is a wasm url relative from build output chunk.
      */
     const wasmPath: string;
     export default wasmPath;
 }
+
+declare module 'external:emscripten/*.wasm.fallback' {
+    /**
+     * This is a wasm fallback url relative from build output chunk.
+     */
+    const wasmFallbackPath: string;
+    export default wasmFallbackPath;
+}
+
+declare module 'external:emscripten/*.js.mem' {
+    /**
+     * This is a js.mem url relative from build output chunk.
+     */
+    const jsMemPath: string;
+    export default jsMemPath;
+}

emscripten/spine/spine.d.ts

@@ -2,7 +2,11 @@ declare module 'external:emscripten/spine/spine.asm.js' {
     export default SpineWasm;
 }
 
-declare module 'external:emscripten/spine/spine.js' {
+declare module 'external:emscripten/spine/spine.wasm.js' {
+    export default SpineWasm;
+}
+
+declare module 'external:emscripten/spine/spine.wasm.fallback.js' {
     export default SpineWasm;
 }
 
@@ -10,10 +14,7 @@ declare module 'external:emscripten/spine/spine.js' {
 declare function SpineWasm (moduleOptions?: any): Promise<void>;
 
 declare namespace SpineWasm {
-    type ptr = number;
     interface instance {
-        spine: any;
-        memory: any;
         spineWasmInit(): void;
         spineWasmDestroy(): void;
     }