MAke a separate scratch for decompressor

include/grub/decompressor.h

@@ -23,6 +23,12 @@ void
 grub_decompress_core (void *src, void *dst, unsigned long srcsize,
 		      unsigned long dstsize);
 
+void
+find_scratch (void *src, void *dst, unsigned long srcsize,
+	      unsigned long dstsize);
+
 #define GRUB_DECOMPRESSOR_DICT_SIZE (1 << 16)
 
+extern void *grub_decompressor_scratch;
+
 #endif