Some changes to permit a clean build on OpenBSD. The spec tests are not yet addressed but the build is clean and libiconv now correctly attaches to the OpenBSD versions of the function names.
Filter out over-strict llvm-config --cxxflags flags encountered on Op…
Cast string constant to char * before assigning to tm_64->tm_zone
Accommodate iconv library versions that have function names of the fo…
…rm libiconv_open, etc (OpenBSD)