Description:

------------
Please accept my apologies if this is already reported - I searched and
didn't find it.

When configuring PHP for x86_64, it is necessary to use:
--with-libdir=lib64

When you compile MySQL from source, it does not place its files in
lib64, but rather lib.

MySQL was configured using:
--prefix=/usr/local/mysql

Configuring PHP using:
--with-mysql=/usr/local/mysql
fails with this:
checking for MySQL support... yes
checking for specified location of the MySQL UNIX socket... no
checking for MySQL UNIX socket location... no
configure: error: Cannot find libmysqlclient under /usr/local/mysql.
Note that the MySQL client library is not bundled anymore!

This fixes the problem: cd /usr/local/mysql ln -s lib lib64

When PHP is configured using --with-mysql= and
--with-libdir=, it should search / and then
/lib

Reproduce code:
---------------
./configure --with-mysql= when MySQL is compiled from
source code

Expected result:
----------------
successful configure

Actual result:
--------------
configure fails with:
checking for MySQL support... yes
checking for specified location of the MySQL UNIX socket... no
checking for MySQL UNIX socket location... no
configure: error: Cannot find libmysqlclient under /usr/local/mysql.
Note that the MySQL client library is not bundled anymore!