I can't reproduce it at home on Solaris x86.  

Could it be
specific to Solaris on SPARC?  I just tried at work and
it happens with command line compiler too.  I don't think
I modified config.sh (didn't need to thanks to the changes
you made!) or finish_freezing.  And CFLAGS doesn't have
any optimization options.

Actually, I just found out that I *can* reproduce it on 
Solaris x86 if I finalize.  Apparently the "optimize"
variable for finalization is "-xO2" and "wkoptimize" is
"".  So on x86 platform, it is doubled only if I finalize
and only if CFLAGS environment variable is set.  CFLAGS
must also be set for it to happen on Solaris SPARC.