OK, seriously, we fixed the TB to handle this now

uriloader/exthandler/Makefile.in

@@ -41,11 +41,7 @@ else
 OSDIR	= unix
 endif
 
-ifeq ($(MOZ_OS2_TOOLS),VACPP)
-OSHELPER	= $(OSDIR)/nsOSHelperAppService.cpp
-else
 OSHELPER	= nsOSHelperAppService.cpp
-endif
 
 EXPORTS = 	nsExternalHelperAppService.h \
 		$(OSDIR)/nsOSHelperAppService.h \