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
@@ -238,3 +238,7 @@
 #endif /* i386 || _i386 || _I386 || __i386 */
 
 #endif /* !USE_ZLIB */
+
+#ifdef __ELF__
+.section .note.GNU-stack,"",%progbits
+#endif