This makes LLDB launch and create a REPL, specifying no target so that the REPL
can create one for itself. Also added the "--repl-language" option, which
specifies the language to use. Plumbed the relevant arguments and errors
through the REPL creation mechanism.
llvm-svn: 250773
A REPL takes over the command line and typically treats input as source code.
REPLs can also do code completion. The REPL class allows its subclasses to
implement the language-specific functionality without having to know about the
IOHandler-specific internals.
Also added a PluginManager-based way of getting to a REPL given a language and
a target.
Also brought in some utility code and expression options that are useful for
REPLs, such as line offsets for expressions, ANSI terminal coloring of errors,
and a few IOHandler convenience functions.
llvm-svn: 250753
Eugene Zelenko