[Bug libitm/63781] potential linkage issue with libitm.1.dylib

[howarth at bromo dot med.uc.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63781

--- Comment #6 from howarth at bromo dot med.uc.edu ---
Okay, I see the missing linkage on libstdc++ is intentional...

# Force link with C, not C++.  For now, while we're using C++ we don't
# want or need libstdc++.
libitm_la_DEPENDENCIES = $(libitm_version_dep)
libitm_la_LINK = $(LINK) $(libitm_la_LDFLAGS)
libitm_la_LDFLAGS = $(libitm_version_info) $(libitm_version_script)

but it would be good to know what the impact of the undefined ___cxa_tm_cleanup
has on libitm and what we should do about it.