patterns: Added pattern file for Apple PBZX compressed streams (#63)

This is used by Apple for Xcode .xip files (cpio in pbzx in xar), OTA
updates of iOS, and other files.

patterns/pbzx.hexpat

@@ -0,0 +1,30 @@
+// pbzx compression stream
+// Used by Apple on .xip files and OTA updates.
+//
+// Copyright (c) 2022 Nicolás Alvarez <nicolas.alvarez@gmail.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <std/mem.pat>
+
+#pragma endian big
+
+#define SHOW_DATA 0
+
+struct Chunk {
+    u64 uncompressed_size;
+    u64 compressed_size;
+    if (SHOW_DATA) {
+        u8 data[compressed_size] [[sealed]];
+    } else {
+        padding[compressed_size];
+    }
+};
+
+struct PBZX {
+    char magic[4];
+    u64 chunk_size;
+    Chunk chunks[while(!std::mem::eof())];
+};
+
+PBZX pbzx @ 0;