[PATCH 1/3] Mark __libc_multiple_libcs with attribute_hidden [BZ #18822]

[Florian Weimer]

* H. J. Lu:

> 	[BZ #18822]
> 	* csu/libc-start.c (__libc_multiple_libcs): Add attribute_hidden.
> 	* elf/dl-open.c (__libc_multiple_libcs): Likewise.

Please put a hidden declaration into a header file instead.