* Add some procedures to path_unix to mirror the path_windows API

* Add files stat_linux and dir_linux to mirror the stat/dir_windows API
* Add helper functions to os_linux that are used by the above

core/path/filepath/path_unix.odin

@@ -1,6 +1,26 @@
 //+build linux, darwin, freebsd
 package filepath
 
+import "core:strings"
+import "core:os"
+
 SEPARATOR :: '/';
 SEPARATOR_STRING :: `/`;
 LIST_SEPARATOR :: ':';
+
+abs :: proc(path: string, allocator := context.allocator) -> (string, bool) {
+	full_path, err := os.absolute_path_from_relative(path);
+	if err != os.ERROR_NONE {
+		return "", false;
+	}
+	return full_path, true;
+}
+
+join :: proc(elems: ..string, allocator := context.allocator) -> string {
+	s := strings.join(elems, SEPARATOR_STRING);
+	return s;
+}
+
+is_abs :: proc(path: string) -> bool {
+	return (path[0] == '/');
+}