patch 8.2.0782: cannot build with Lua on MS-Windows

Problem:    Cannot build with Lua on MS-Windows.
Solution:   Add DLL symbol for luaL_Loadstring. (Ken Takata)
diff --git a/src/if_lua.c b/src/if_lua.c
index 060cb38..9a3081b 100644
--- a/src/if_lua.c
+++ b/src/if_lua.c
@@ -119,6 +119,7 @@
 #define luaL_buffinit dll_luaL_buffinit
 #define luaL_addlstring dll_luaL_addlstring
 #define luaL_pushresult dll_luaL_pushresult
+#define luaL_loadstring dll_luaL_loadstring
 // lua
 #if LUA_VERSION_NUM <= 501
 #define lua_tonumber dll_lua_tonumber
@@ -213,6 +214,7 @@
 void (*dll_luaL_buffinit) (lua_State *L, luaL_Buffer *B);
 void (*dll_luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l);
 void (*dll_luaL_pushresult) (luaL_Buffer *B);
+int (*dll_luaL_loadstring) (lua_State *L, const char *s);
 // lua
 #if LUA_VERSION_NUM <= 501
 lua_Number (*dll_lua_tonumber) (lua_State *L, int idx);
@@ -325,6 +327,7 @@
     {"luaL_buffinit", (luaV_function) &dll_luaL_buffinit},
     {"luaL_addlstring", (luaV_function) &dll_luaL_addlstring},
     {"luaL_pushresult", (luaV_function) &dll_luaL_pushresult},
+    {"luaL_loadstring", (luaV_function) &dll_luaL_loadstring},
     // lua
 #if LUA_VERSION_NUM <= 501
     {"lua_tonumber", (luaV_function) &dll_lua_tonumber},
diff --git a/src/version.c b/src/version.c
index 641aa88..f047bde 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    782,
+/**/
     781,
 /**/
     780,