Log Message:
devel/ruby-ffi: update to 1.11.1

Update ruby-ffi to 1.11.1.

1.11.1 / 2019-05-20
-------------------

Changed:
* Raise required ruby version to >=2.0. #699, #700
* Fix a possible linker error on ruby < 2.3 on Linux.

1.11.0 / 2019-05-17
-------------------

Added:
* Add ability to disable or force use of system libffi. #669
  Use like `gem inst ffi -- --enable-system-libffi` .
* Add ability to call FFI callbacks from outside of FFI call frame. #584
* Add proper documentation to FFI::Generator and ::Task
* Add gemspec metadata. #696, #698

Changed:
* Fix stdcall on Win32. #649, #669
* Fix load paths for FFI::Generator::Task
* Fix FFI::Pointer#read_string(0) to return a binary String. #692
* Fix benchmark suite so that it runs on ruby-2.x
* Move FFI::Platform::CPU from C to Ruby. #663
* Move FFI::StructByReference to Ruby. #681
* Move FFI::DataConverter to Ruby (#661)
* Various cleanups and improvements of specs and benchmarks

Removed:
* Remove ruby-1.8 and 1.9 compatibility code. #683
* Remove unused spec files. #684