TruffleRuby - GraalVM Community Edition 1.0 RC12

Bug fixes:

• Fixed a bug with String#lines and similar methods with multibyte
  characters (#1543).
• Fixed an issue with String#{encode,encode!} double-processing strings
  using XML conversion options and a new destination encoding (#1545).
• Fixed a bug where a raised cloned exception would be caught as the
  original exception (#1542).
• Fixed a bug with StringScanner and patterns starting with ^ (#1544).
• Fixed Enumerable::Lazy#uniq with infinite streams (#1516).

Compatibility:

• Change to a new system for handling Ruby objects in C extensions which
  greatly increases compatibility with MRI.
• Implemented BigDecimal#to_r (#1521).
• Symbol#to_proc now returns -1 like on MRI (#1462).