Building mozilla with linuxthreads

[Joe Kelsey]

I want to build mozilla with linuxthreads (devel/linuxthreads) instead 
of native -pthread/libc_r.  I want to do this to try to support Flash 6 
using the linus Flash 6 plugin.  The standard linux Flash 6 plugin 
requires a pthread library which uses structures compatible with the 
Linux pthread_mutex_t and pthread_once_t sizes rather than the FreeBSD 
native opaque types.

The linuxthreads library requires that I use the flags

'-D_THREAD_SAFE -I/usr/local/include/pthread/linuxthreads -llthread 
-llgcc_r'

instead of -pthread when compiling.

Can anyone tell me an easy way to find where the -pthread flag enters 
the compilation stream so I can remove it and substutite the 
linuxthreads options?

/Joe