Previously, before loading the REPL language-specific init file, lldb
checked the selected target language in which case it returned an unknown
language type with the REPL target.
Instead, the patch calls Language::GetLanguagesSupportingREPLs and
look for the first element of that set. In case lldb was not configured
with a REPL language, then, it will just stop sourcing the REPL init
file and fallback to the original logic (continuing with the default
Signed-off-by: Med Ismail Bennani <firstname.lastname@example.org>