Support IrExpressionBody in codegen

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt

@@ -124,6 +124,9 @@ class ExpressionCodegen(
             //for implicit return
             mv.areturn(Type.VOID_TYPE)
         }
+        else if (irFunction.body is IrExpressionBody) {
+            mv.areturn(returnType)
+        }
         writeLocalVariablesInTable(info)
         mv.visitEnd()
     }
@@ -367,6 +370,10 @@ class ExpressionCodegen(
         return expression.onStack
     }
 
+    override fun visitExpressionBody(body: IrExpressionBody, data: BlockInfo): StackValue {
+        return body.expression.accept(this, data)
+    }
+
     override fun visitElement(element: IrElement, data: BlockInfo): StackValue {
         TODO("not implemented for $element") //To change body of created functions use File | Settings | File Templates.
     }