systemtap compile fail on F18(i686) and F19(i686)

[Masanari Iida]

Hello.
After commit id 3d0a328dd, compile systemtap on F18(i686)
and F19(i686) failed.  This symptom can be reproduced only on i686.
Before 3d0a328dd, it can be compiled without error even on i686.

Error messages
  CXXLD    stap
/bin/ld: stap-main.o: undefined reference to symbol
'pthread_create@@GLIBC_2.1' /bin/ld: note: 'pthread_create@@GLIBC_2.1'
is defined in DSO /lib/libpthread.so.0 so try adding it to the linker command
line /lib/libpthread.so.0: could not read symbols: Invalid operation
collect2: error: ld returned 1 exit status
make[2]: *** [stap] Error 1

Workaround.
Add  LDFLAGS = -pthread  in Makefile.

If I compile the snapshot-20130504 on RHEL6, it can be compiled
successfully on both i686 and x86_64 case without error.
So I guess the problem exist on F18(i686) and F19 (i686).

I would like to report this error to Red Hat Bugzilla.
In that case which component do I want to select?

TIA

Masanari Iida