Added Integer>>#round to be polymorphic with Double

This is useful because for instance #sqrt will return an Integer if the results fits into one (is this actually a good idea? Sounds strange when putting this here.)

Signed-off-by: Stefan Marr <git@stefan-marr.de>

Kernel.som

@@ -167,6 +167,7 @@ class Kernel vmMirror: vmMirror = Object <: Value (
     public abs         = ( ^ (self < 0) ifTrue: (0 - self) ifFalse: self )
     public sqrt        = ( ^ vmMirror intSqrt: self )
     public negated     = ( ^ 0 - self )
+    public round       = ( ^ self ) (* added to be polymorphic with Double *)
 
     'Bit operations'
     public & argument  = ( ^ vmMirror int: self bitAnd: argument )