mx jol: let user select from found classes, skip duplicates

--HG--
extra : rebase_source : 57576dbb04962b0901ce07c61037e051003a6953
Truffle: remove CompilerDirectives.unsafeFrameCast

--HG--
extra : rebase_source : bdf3c46f72263df546978426c179ca7bb1b82861
Truffle: add TruffleRuntime#getCapability method

--HG--
extra : rebase_source : 311c3fd9d29e7dfad36ef3f8363aed8c70bf87ff
Truffle: add a test to track an ImplicitCast bug

--HG--
extra : amend_source : bd0943e9754dd797803b8e6151373a2621f8bbae