Fix to allow using Smalltalk blocks even after the method containing
their definition has returned.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/steptalk/trunk@36420 72102866-910b-0410-8b05-ffd578937521
Follow Smalltalk convention to return the receiver from a method
without an explicit return statement.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/steptalk/trunk@36421 72102866-910b-0410-8b05-ffd578937521
Fix stack underflow exception when computing the value of an empty
block.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/steptalk/trunk@36422 72102866-910b-0410-8b05-ffd578937521