Add Lua example to vendor\lua as well as basic tests.

vendor/lua/README.md

@@ -1,12 +1,50 @@
 # Lua in Odin
 
-```odin
-import lua "vendor:lua/5.4" // or whatever version you want
-```
-
 Lua packages
 
 * `vendor:lua/5.1` (version 5.1.5)
 * `vendor:lua/5.2` (version 5.2.4)
 * `vendor:lua/5.3` (version 5.3.6)
-* `vendor:lua/5.4` (version 5.4.2)
+* `vendor:lua/5.4` (version 5.4.2)
+
+With custom context-based allocator:
+
+```odin
+package lua_example_with_context
+
+import "core:fmt"
+import lua "vendor:lua/5.4" // or whatever version you want
+import "core:c"
+import "base:runtime"
+
+state: ^lua.State
+
+lua_allocator :: proc "c" (ud: rawptr, ptr: rawptr, osize, nsize: c.size_t) -> (buf: rawptr) {
+	old_size := int(osize)
+	new_size := int(nsize)
+	context = (^runtime.Context)(ud)^
+
+	if ptr == nil {
+		data, err := runtime.mem_alloc(new_size)
+		return raw_data(data) if err == .None else nil
+	} else {
+		if nsize > 0 {
+			data, err := runtime.mem_resize(ptr, old_size, new_size)
+			return raw_data(data) if err == .None else nil
+		} else {
+			runtime.mem_free(ptr)
+			return
+		}
+	}
+}
+
+main :: proc() {
+	_context := context
+	state = lua.newstate(lua_allocator, &_context)
+	defer lua.close(state)
+
+	lua.L_dostring(state, "return 'somestring'")
+	str := lua.tostring(state, -1)
+	fmt.println(str)
+}
+```