OK, "i686-apple-darwin11-llvm-g++-4.2 (GCC) 4.2.1 (Based on Apple Inc.

OK, "i686-apple-darwin11-llvm-g++-4.2 (GCC) 4.2.1 (Based on Apple Inc.
build 5658) (LLVM build 2336.11.00)" likes -Wmissing-prototypes but not
-Wmissing-declarations and G++ 4.8.2 likes -Wmissing-declarations but
not -Wmissing-prototypes, so check whether *either* of them requires
-Werror in order to be detected as NSFC++.

Fix a copy-and-pasteo while we're at it.

Don't treat a different willingness to accept
-Wmissing-{prototypes,declarations} as an indication that you have
mismatched C and C++ compilers.

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@54468 f5534014-38df-0310-8fa8-9805f1628bb7