pop.patch

diff --git a/truffle/src/main/java/org/jruby/truffle/nodes/core/ArrayNodes.java b/truffle/src/main/java/org/jruby/truffle/nodes/core/ArrayNodes.java
index d731818..1bb9e27 100644
--- a/truffle/src/main/java/org/jruby/truffle/nodes/core/ArrayNodes.java
+++ b/truffle/src/main/java/org/jruby/truffle/nodes/core/ArrayNodes.java
@@ -2427,7 +2427,7 @@ public abstract class ArrayNodes {
 
     }
 
-    @CoreMethod(names = "pop", raiseIfFrozenSelf = true)
+    @CoreMethod(names = "pop", needsSelf = true, raiseIfFrozenSelf = true, optional = 1)
     public abstract static class PopNode extends ArrayCoreMethodNode {
 
         public PopNode(RubyContext context, SourceSection sourceSection) {
@@ -2441,12 +2441,12 @@ public abstract class ArrayNodes {
         public abstract Object executePop(RubyArray array);
 
         @Specialization(guards = "isNull")
-        public Object popNil(RubyArray array) {
+        public Object popNil(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) {
             return nil();
         }
 
         @Specialization(guards = "isIntegerFixnum", rewriteOn = UnexpectedResultException.class)
-        public int popIntegerFixnumInBounds(RubyArray array) throws UnexpectedResultException {
+        public int popIntegerFixnumInBounds(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) throws UnexpectedResultException {
             if (CompilerDirectives.injectBranchProbability(CompilerDirectives.UNLIKELY_PROBABILITY, array.getSize() == 0)) {
                 throw new UnexpectedResultException(nil());
             } else {
@@ -2458,7 +2458,7 @@ public abstract class ArrayNodes {
         }
 
         @Specialization(contains = "popIntegerFixnumInBounds", guards = "isIntegerFixnum")
-        public Object popIntegerFixnum(RubyArray array) {
+        public Object popIntegerFixnum(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) {
             if (CompilerDirectives.injectBranchProbability(CompilerDirectives.UNLIKELY_PROBABILITY, array.getSize() == 0)) {
                 return nil();
             } else {
@@ -2470,7 +2470,7 @@ public abstract class ArrayNodes {
         }
 
         @Specialization(guards = "isLongFixnum", rewriteOn = UnexpectedResultException.class)
-        public long popLongFixnumInBounds(RubyArray array) throws UnexpectedResultException {
+        public long popLongFixnumInBounds(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) throws UnexpectedResultException {
             if (CompilerDirectives.injectBranchProbability(CompilerDirectives.UNLIKELY_PROBABILITY, array.getSize() == 0)) {
                 throw new UnexpectedResultException(nil());
             } else {
@@ -2482,7 +2482,7 @@ public abstract class ArrayNodes {
         }
 
         @Specialization(contains = "popLongFixnumInBounds", guards = "isLongFixnum")
-        public Object popLongFixnum(RubyArray array) {
+        public Object popLongFixnum(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) {
             if (CompilerDirectives.injectBranchProbability(CompilerDirectives.UNLIKELY_PROBABILITY, array.getSize() == 0)) {
                 return nil();
             } else {
@@ -2494,7 +2494,7 @@ public abstract class ArrayNodes {
         }
 
         @Specialization(guards = "isFloat", rewriteOn = UnexpectedResultException.class)
-        public double popFloatInBounds(RubyArray array) throws UnexpectedResultException {
+        public double popFloatInBounds(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) throws UnexpectedResultException {
             if (CompilerDirectives.injectBranchProbability(CompilerDirectives.UNLIKELY_PROBABILITY, array.getSize() == 0)) {
                 throw new UnexpectedResultException(nil());
             } else {
@@ -2506,7 +2506,7 @@ public abstract class ArrayNodes {
         }
 
         @Specialization(contains = "popFloatInBounds", guards = "isFloat")
-        public Object popFloat(RubyArray array) {
+        public Object popFloat(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) {
             if (CompilerDirectives.injectBranchProbability(CompilerDirectives.UNLIKELY_PROBABILITY, array.getSize() == 0)) {
                 return nil();
             } else {
@@ -2518,7 +2518,7 @@ public abstract class ArrayNodes {
         }
 
         @Specialization(guards = "isObject")
-        public Object popObject(RubyArray array) {
+        public Object popObject(RubyArray array, UndefinedPlaceholder undefinedPlaceholder) {
             if (CompilerDirectives.injectBranchProbability(CompilerDirectives.UNLIKELY_PROBABILITY, array.getSize() == 0)) {
                 return nil();
             } else {