Fix https://github.com/llvm/llvm-project/issues/85343
When build lambda expression in lambda instantiation, `ThisType` is
required in `Sema::CheckCXXThisCapture` to build `this` capture. Set
`this` type by import `Sema::CXXThisScopeRAII` and it will be used later
in lambda expression transformation.
Co-authored-by: huqizhi <836744285@qq.com>
