[OpenBSD] Define _WCHAR_H_CPLUSPLUS_98_CONFORMANCE_ only when using Clang.
[OpenBSD] Define _WCHAR_H_CPLUSPLUS_98_CONFORMANCE_ only when using Clang.

tstack/lnav,tstack/lnav,tstack/lnav,sureshsundriyal/lnav,sureshsundriyal/lnav,sureshsundriyal/lnav,tstack/lnav,sureshsundriyal/lnav