Make sure that the asm files don't incorrectly trigger an executable
stack marking in the final shared library.  That's bad, mmmkay.

--- unzip/crc_i386.S
+++ unzip/crc_i386.S
@@ -302,3 +302,7 @@
 #endif /* i386 || _i386 || _I386 || __i386 */
 
 #endif /* !USE_ZLIB && !CRC_TABLE_ONLY */
+
+#if defined(__linux__) && defined(__ELF__)
+.section .note.GNU-stack,"",%progbits
+#endif