The motivation here is that we don't want to pollute the SBAPI with
getters/setters for expression evaluation options that only apply to a
single language. The ultimate goal would be to have plugins register
additional options to the `expression` command when the plugin is
loaded. This patch only provides the minimal `SBExpressionOptions`
interface to set an option with an arbitrary name, which the language
plugin knows how to interpret. The underlying options dictionary is an
`StructuredData::Dictionary` so we can map strings to values of any
type. But the SBAPI just exposes setting a boolean value. Future
overloads of `SetLanguageOption` can provide setters for more types.
The boolean setter/getter will be used for the C++-specific option being
introduced in: https://github.com/llvm/llvm-project/pull/177926
Instead of maintaining separate swig interface files, we can use the API
headers directly. They implement the exact same C++ APIs and we can
conditionally include the python extensions as needed. To remove the
swig extensions from the API headers when building the LLDB
framework, we can use the unifdef tool when it is available. Otherwise
we just copy them as-is.
Differential Revision: https://reviews.llvm.org/D142926
