Description of problem:
If glibc 2.7-2 rebuilded as i386 - old ok.
If as i586 -- build failed, both as auxarch and not-auxarch.

Version-Release number of selected component (if applicable):
glibc-2.7-2

How reproducible:
always.

Steps to Reproduce:
1. rpmbuild -ba --target i386 glibc.spec --- all ok.
2. rpmbuild -ba --target i586 glibc.spec --- build failed, 
   error: multiple definition of `__memcpy_chk' .....
3. drop i586 from spec: %define auxarches i586 ...
    rpmbuild  --target i586 glibc.spec --- build failed, 
  
Actual results:
Build failed.

Expected results:
Build must be successful both for i386 and i586.

Additional info:
Most of packages I build as i586 or i686.