[truffle] Implement postinc and postdec ops

Author: pmurias

nqp-truffle.nqp

@@ -179,6 +179,23 @@ class QAST::OperationsTruffle {
         add_simple_op($math-op ~ '_i', $INT, [$INT, $INT]);
     }
 
+    for <postinc postdec> -> $op {
+        add_op($op, sub ($comp, $node, :$want) {
+            my $old_value := $comp.as_truffle($node[0], :want($INT));
+            my str $action := $op eq 'postinc' ?? 'add_i' !! 'sub_i';
+            my $do_action := $comp.as_truffle(
+                QAST::Op.new(
+                    :op('bind'),
+                    $node[0],
+                    QAST::Op.new(:op($action),$node[0],QAST::IVal.new(:value(1)))
+                ),
+                :want($VOID)
+            );
+
+            TAST.new($INT, ['old-int-value', $old_value.tree, $do_action.tree]);
+       });
+    }
+
     # explicit takeclosure is used by the JVM backend we no-op it.
     add_op('takeclosure', sub ($comp, $node, :$want) {
         $comp.as_truffle($node[0], :want($want));

src/vm/jvm/runtime/org/perl6/nqp/truffle/nodes/variables/NQPOldIntValueNode.java

@@ -0,0 +1,24 @@
+package org.perl6.nqp.truffle.nodes.expression;
+import com.oracle.truffle.api.frame.VirtualFrame;
+import com.oracle.truffle.api.nodes.NodeInfo;
+import org.perl6.nqp.truffle.nodes.NQPNode;
+import org.perl6.nqp.dsl.Deserializer;
+
+@NodeInfo(shortName = "old-int-value")
+public final class NQPOldIntValueNode extends NQPNode {
+    @Child private NQPNode oldValueNode;
+    @Child private NQPNode bindNewValueNode;
+
+    @Deserializer("old-int-value")
+    public NQPOldIntValueNode(NQPNode oldValueNode, NQPNode bindNewValueNode) {
+        this.oldValueNode = oldValueNode;
+        this.bindNewValueNode = bindNewValueNode;
+    }
+
+    @Override
+    public long executeInt(VirtualFrame frame) {
+        long oldValue = this.oldValueNode.executeInt(frame);
+        this.bindNewValueNode.execute(frame);
+        return oldValue;
+    }
+}