Please describe the problem:
Currently libcroco fails to build if you're using the --as-needed linker flag, 
because libcroco itself does not link against libxml2 and rather waits for the 
final executable to link against it (that's a very positive thinking). 
The attached patch adds the link to libxml2 directly during creation of 
libcroco.so, thus allowing to complete the final build of the package when 
using --as-needed. 

Steps to reproduce:
 

Actual results:


Expected results:


Does this happen every time?


Other information: