LibCompress: Add support for dynamic deflate blocks.

Author: https://github.com/asynts
Commit: 0ebf56efb0
Pull-request: https://github.com/SerenityOS/serenity/pull/3362
Reviewed-by: https://github.com/alimpfard

Libraries/LibCompress/Deflate.h

@@ -99,7 +99,7 @@ public:
 private:
     u32 decode_run_length(u32);
     u32 decode_distance(u32);
-    void decode_codes(CanonicalCode&, CanonicalCode&);
+    void decode_codes(CanonicalCode& literal_code, Optional<CanonicalCode>& distance_code);
 
     bool m_read_final_bock { false };