libarchive: Limit 7zip and zstd compression level to 6 on AIX

Extend commit 6287b02147 (libarchive: Limit xz compression level to 6 on
AIX, 2021-08-24, v3.22.0-rc1~188^2) to cover 7zip and zstd.

Utilities/cmlibarchive/libarchive/archive_write_add_filter_zstd.c

@@ -265,6 +265,11 @@ archive_compressor_zstd_options(struct archive_write_filter *f, const char *key,
 		if (level < minimum || level > maximum) {
 			return (ARCHIVE_WARN);
 		}
+#ifdef _AIX
+		if (level > 6) {
+			level = 6;
+		}
+#endif
 		data->compression_level = (int)level;
 		return (ARCHIVE_OK);
 	} else if (strcmp(key, "threads") == 0) {

Utilities/cmlibarchive/libarchive/archive_write_set_format_7zip.c

@@ -511,6 +511,11 @@ _7z_options(struct archive_write *a, const char *key, const char *value)
 				"compression-level option value `%ld' out of range", lvl);
 			return (ARCHIVE_FAILED);
 		}
+#ifdef _AIX
+		if (lvl > 6) {
+			lvl = 6;
+		}
+#endif
 
 		// Note: we don't know here if this value is for zstd (negative to ~22),
 		// or zlib-style 0-9. If zstd is enabled but not in use, we will need to

Utilities/cmlibarchive/libarchive/archive_write_set_format_zip.c

@@ -1365,6 +1365,11 @@ archive_write_zip_header(struct archive_write *a, struct archive_entry *entry)
 		int zstd_compression_level = zip->compression_level == 1
 			? ZSTD_minCLevel() // ZSTD_minCLevel is negative !
 			: (zip->compression_level - 1) * ZSTD_maxCLevel() / 8;
+#ifdef _AIX
+		if (zstd_compression_level > 6) {
+			zstd_compression_level = 6;
+		}
+#endif
 		zip->stream.zstd.context = ZSTD_createCStream();
 		size_t zret = ZSTD_initCStream(zip->stream.zstd.context, zstd_compression_level);
 		if (ZSTD_isError(zret)) {