[tlbuild] always static libstdc++?

[Karl Berry]

Hi TL builders - do any of your platforms *not* require the
KPSE_CXX_HACK to statically link the C++ runtime for the native TL
binaries? Specifically, in the output from configure, these lines:

checking for statically linking C++ runtime library... ok
configure: using -nodefaultlibs -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic -lm -lgcc_eh -lgcc -lc -lgcc_eh -lgcc

If the correct arguments can't be determined, it says "not supported"
instead of "ok".

and also in the configure summary at the end:
   enable_cxx_runtime_hack:      yes

If this is always needed for our native TL binaries, I'm going to change
the Autoconf macro that checks for it to abort if
--enable-native-texlive-build is given and the necessary options aren't
discovered. (Having just wasted some time trying to figure out why my
binaries were no longer statically linked and not noticing that crucial
configure line ...)

On the other hand, I thought there might be some platforms where we do
distribute binaries with the C++ libraries dynamically linked, for
whatever reason, and that's ok. (So then I wouldn't make that change.)

Please let me know ... --thanks, karl.