[asyncify] Refactor argument restoring under wasm64. NFC

This change was split out from my larger change to switch to table64.

When we use MEMORY64 + ASYNCIFY=1 we have add multiple wrappers to the
wasm exports.  This change basically moves the argument restoration to
the outside rather than doing int the wrapper.  This means that all the
different wrappers see the restored arguments, not just the asyncify
wrapper (which is the first/lowest level wrapper.

src/library_async.js

@@ -95,12 +95,12 @@ addToLibrary({
       }
     },
 #if ASYNCIFY == 1 && MEMORY64
-    saveOrRestoreRewindArguments(funcName, passedArguments) {
-      if (passedArguments.length === 0) {
-        return Asyncify.rewindArguments[funcName] || []
-      }
+    saveRewindArguments(funcName, passedArguments) {
       return Asyncify.rewindArguments[funcName] = Array.from(passedArguments)
     },
+    restoreRewindArguments(funcName) {
+      return Asyncify.rewindArguments[funcName] || []
+    },
 #endif
     instrumentWasmExports(exports) {
 #if ASYNCIFY_DEBUG
@@ -130,14 +130,9 @@ addToLibrary({
             try {
 #endif
 #if ASYNCIFY == 1 && MEMORY64
-              // When re-winding, the arguments to a function are ignored.  For i32 arguments we
-              // can just call the function with no args at all since and the engine will produce zeros
-              // for all arguments.  However, for i64 arguments we get `undefined cannot be converted to
-              // BigInt`.
-              return original(...Asyncify.saveOrRestoreRewindArguments(x, args));
-#else
-              return original(...args);
+              Asyncify.saveRewindArguments(x, args);
 #endif
+              return original(...args);
 #if ASYNCIFY == 1
             } finally {
               if (!ABORT) {
@@ -265,12 +260,16 @@ addToLibrary({
       {{{ makeSetValue('ptr', C_STRUCTS.asyncify_data_s.rewind_id, 'rewindId', 'i32') }}};
     },
 
+    getDataRewindFuncName(ptr) {
+      var id = {{{ makeGetValue('ptr', C_STRUCTS.asyncify_data_s.rewind_id, 'i32') }}};
+      var name = Asyncify.callStackIdToName[id];
+      return name;
+    },
+
 #if RELOCATABLE
     getDataRewindFunc__deps: [ '$resolveGlobalSymbol' ],
 #endif
-    getDataRewindFunc(ptr) {
-      var id = {{{ makeGetValue('ptr', C_STRUCTS.asyncify_data_s.rewind_id, 'i32') }}};
-      var name = Asyncify.callStackIdToName[id];
+    getDataRewindFunc(name) {
       var func = wasmExports[name];
 #if RELOCATABLE
       // Exported functions in side modules are not listed in `wasmExports`,
@@ -283,14 +282,23 @@ addToLibrary({
     },
 
     doRewind(ptr) {
-      var start = Asyncify.getDataRewindFunc(ptr);
+      var name = Asyncify.getDataRewindFuncName(ptr);
+      var func = Asyncify.getDataRewindFunc(name);
 #if ASYNCIFY_DEBUG
-      dbg('ASYNCIFY: start:', start);
+      dbg('ASYNCIFY: doRewind:', name);
 #endif
       // Once we have rewound and the stack we no longer need to artificially
       // keep the runtime alive.
       {{{ runtimeKeepalivePop(); }}}
-      return start();
+#if MEMORY64
+      // When re-winding, the arguments to a function are ignored.  For i32 arguments we
+      // can just call the function with no args at all since and the engine will produce zeros
+      // for all arguments.  However, for i64 arguments we get `undefined cannot be converted to
+      // BigInt`.
+      return func(...Asyncify.restoreRewindArguments(name));
+#else
+      return func();
+#endif
     },
 
     // This receives a function to call to start the async operation, and
@@ -441,7 +449,7 @@ addToLibrary({
     },
     makeAsyncFunction(original) {
 #if ASYNCIFY_DEBUG
-      dbg('asyncify: returnPromiseOnSuspend for', original);
+      dbg('asyncify: makeAsyncFunction for', original);
 #endif
       return WebAssembly.promising(original);
     },