[truffle] Implement nqp::setmethcache

src/vm/jvm/Truffle.nqp

@@ -272,6 +272,8 @@ class QAST::OperationsTruffle {
     add_simple_op('scwbenable', $INT, []);
     add_simple_op('scwbdisable', $INT, []);
 
+    add_simple_op('setmethcache', $OBJ, [$OBJ, $OBJ], :decont(0));
+
     add_op('list_b', sub ($comp, $node, :$want) {
         my @cuids;
         for $node.list -> $block {

src/vm/jvm/runtime/org/perl6/nqp/truffle/nodes/sixmodel/NQPSetmethcacheNode.java

@@ -0,0 +1,27 @@
+package org.perl6.nqp.truffle.nodes.sixmodel;
+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.truffle.nodes.NQPObjNodeWithSTableGetting;
+import org.perl6.nqp.truffle.runtime.NQPHash;
+import org.perl6.nqp.dsl.Deserializer;
+
+@NodeInfo(shortName = "setmethcache")
+public final class NQPSetmethcacheNode extends NQPObjNodeWithSTableGetting {
+    @Child private NQPNode objNode;
+    @Child private NQPNode methodsNode;
+
+    @Deserializer
+    public NQPSetmethcacheNode(NQPNode objNode, NQPNode methodsNode) {
+        this.objNode = objNode;
+        this.methodsNode = methodsNode;
+    }
+
+    @Override
+    public Object execute(VirtualFrame frame) {
+        Object obj = objNode.execute(frame);
+        NQPHash methodCache = ((NQPHash) methodsNode.execute(frame));
+        getStable(obj).methodCache = methodCache.getContents();
+        return obj;
+    }
+}