Add package path/filepath; Add os.stat for windows (TODO: unix)

core/path/filepath/path_windows.odin

@@ -0,0 +1,71 @@
+package filepath
+
+import "core:strings"
+
+SEPARATOR :: '\\';
+SEPARATOR_STRING :: `\`;
+
+
+reserved_names := []string{
+	"CON", "PRN", "AUX", "NUL",
+	"COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9",
+	"LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
+};
+
+is_reserved_name :: proc(path: string) -> bool {
+	if len(path) == 0 {
+		return false;
+	}
+	for reserved in reserved_names {
+		if strings.equal_fold(path, reserved) {
+			return true;
+		}
+	}
+	return false;
+}
+
+is_UNC :: proc(path: string) -> bool {
+	return volume_name_len(path) > 2;
+}
+
+join :: proc(elems: ..string, allocator := context.allocator) -> string {
+	for e, i in elems {
+		if e != "" {
+			return join_non_empty(elems[i:]);
+		}
+	}
+	return "";
+}
+
+join_non_empty :: proc(elems: []string) -> string {
+	if len(elems[0]) == 2 && elems[0][1] == ':' {
+		i := 1;
+		for ; i < len(elems); i += 1 {
+			if elems[i] != "" {
+				break;
+			}
+		}
+		s := strings.join(elems[i:], SEPARATOR_STRING, context.temp_allocator);
+		s = strings.concatenate({elems[0], s}, context.temp_allocator);
+		return clean(s);
+	}
+
+	s := strings.join(elems, SEPARATOR_STRING, context.temp_allocator);
+	p := clean(s);
+	if !is_UNC(p) {
+		return p;
+	}
+
+	head := clean(elems[0], context.temp_allocator);
+	if is_UNC(head) {
+		return p;
+	}
+	delete(p); // It is not needed now
+
+	tail := clean(strings.join(elems[1:], SEPARATOR_STRING, context.temp_allocator), context.temp_allocator);
+	if head[len(head)-1] == SEPARATOR {
+		return strings.concatenate({head, tail});
+	}
+
+	return strings.concatenate({head, SEPARATOR_STRING, tail});
+}