libarchive: Backport "Fix use of uninitialized values from Huffman table"

Backport libarchive commit `1f5454575f` (cab reader: Fix use of
uninitialized values from Huffman, 2026-04-23).

Add a fuzzing test case to expose this to dynamic analysis tools.

Utilities/cmlibarchive/libarchive/archive_read_support_format_cab.c

@@ -3201,6 +3201,10 @@ lzx_make_huffman_table(struct huffman *hf)
 	bitlen = hf->bitlen;
 	len_avail = hf->len_size;
 	hf->tree_used = 0;
+	/* Initialize table to invalid values */
+	for (i = 0; i < tbl_size; i++) {
+		tbl[i] = (uint16_t)hf->len_size;
+	}
 	for (i = 0; i < len_avail; i++) {
 		uint16_t *p;
 		int len, cnt;