refactor: further simplification using utf-8 autoconversion

Thanks, Pyry!

Author: YoRyan

scripts/build.sh

@@ -20,7 +20,7 @@ cd ../..
 if [[ "$1" == "lua-5.0.3" ]]; then
     emcc -Ithirdparty/$1 thirdparty/$1/lib/liblua.a thirdparty/$1/lib/liblualib.a \
         -s WASM=1 -O3 -o dist/glue/glue-$1.js \
-        -s EXPORTED_RUNTIME_METHODS="['cwrap', 'stackSave', 'stackRestore', 'lengthBytesUTF8', 'allocateUTF8OnStack']" \
+        -s EXPORTED_RUNTIME_METHODS="['cwrap', 'lengthBytesUTF8']" \
         -s MODULARIZE=1 \
         -s ALLOW_TABLE_GROWTH \
         -s EXPORT_NAME="glue" \

src/binding-factory.ts

@@ -165,18 +165,12 @@ const lauxBindings: Record<string, lauxBindingFactoryFunc> = {
                 return (this as LauxLib).luaL_loadstring(L, s) || lua.lua_pcall(L, 0, LUA_MULTRET, 0);
             },
             luaL_loadstring: function(L: LuaState, s: string) {
-                const lastStack = luaGlue.stackSave();
-                const cstr = luaGlue.allocateUTF8OnStack(s) as unknown;
-                const result = (this as LauxLib).luaL_loadbuffer(L, cstr as string, luaGlue.lengthBytesUTF8(s), s);
-                luaGlue.stackRestore(lastStack);
-                return result;
+                return (this as LauxLib).luaL_loadbuffer(L, s, luaGlue.lengthBytesUTF8(s), s);
             },
-            // Note that s has a "number" type, so we can pass a raw pointer
-            luaL_loadbuffer: luaGlue.cwrap("luaL_loadbuffer", "number", ["number", "number", "number", "string"]),
             luaL_newstate: luaGlue.cwrap("lua_open", "number", []),
         }
     },
-    "5.1.x": function(luaGlue: LuaEmscriptenModule, _lua: Lua) {
+    "<=5.1.x": function(luaGlue: LuaEmscriptenModule, _lua: Lua) {
         return {
             luaL_loadbuffer: luaGlue.cwrap("luaL_loadbuffer", "number", ["number", "string", "number", "string"]),
         }

src/glue/glue.ts

@@ -1,9 +1,6 @@
 export interface LuaEmscriptenModule extends EmscriptenModule {
     cwrap: typeof cwrap;
-    stackSave: typeof stackSave;
-    stackRestore: typeof stackRestore;
     lengthBytesUTF8: typeof lengthBytesUTF8;
-    allocateUTF8OnStack: typeof allocateUTF8;
 }
 
 export type EmscriptenModuleFactorySync<T extends EmscriptenModule = EmscriptenModule> = (