Implement correct cloning behaviour for Range.

Author: aardvark179

src/main/java/org/truffleruby/core/range/RangeNodes.java

@@ -192,7 +192,7 @@ protected Object eachObject(RubyObjectRange range) {
 
     }
 
-    @CoreMethod(names = { "dup", "clone" })
+    @CoreMethod(names = "dup")
     public abstract static class DupNode extends UnaryCoreMethodNode {
 
         // NOTE(norswap): This is a hack, as it doesn't copy the ivars.
@@ -241,6 +241,37 @@ protected RubyObjectRange dup(RubyObjectRange range) {
         }
     }
 
+    @CoreMethod(names = "clone")
+    public abstract static class CloneNode extends UnaryCoreMethodNode {
+
+        // NOTE(norswap): This is a hack, as it doesn't copy the ivars.
+        //   We do copy the logical class (but not the singleton class, to be MRI compatible).
+
+        @Specialization
+        protected RubyIntRange cloneIntRange(RubyIntRange range) {
+            return new RubyIntRange(range);
+        }
+
+        @Specialization
+        protected RubyLongRange dupLongRange(RubyLongRange range) {
+            return new RubyLongRange(range);
+        }
+
+        @Specialization
+        protected RubyObjectRange dup(RubyObjectRange range) {
+            final RubyClass logicalClass = range.getLogicalClass();
+            final RubyObjectRange copy = new RubyObjectRange(
+                    logicalClass,
+                    getLanguage().objectRangeShape,
+                    range.excludedEnd,
+                    range.begin,
+                    range.end,
+                    range.frozen);
+            AllocationTracing.trace(copy, this);
+            return copy;
+        }
+    }
+
     @CoreMethod(names = "end")
     public abstract static class EndNode extends CoreMethodArrayArgumentsNode {
 

src/main/java/org/truffleruby/core/range/RubyIntRange.java

@@ -31,7 +31,12 @@ public RubyIntRange(boolean excludedEnd, int begin, int end) {
         this.excludedEnd = excludedEnd;
         this.begin = begin;
         this.end = end;
+    }
 
+    public RubyIntRange(RubyIntRange other) {
+        this.excludedEnd = other.excludedEnd;
+        this.begin = other.begin;
+        this.end = other.end;
     }
 
     @ExportMessage

src/main/java/org/truffleruby/core/range/RubyLongRange.java

@@ -33,6 +33,12 @@ public RubyLongRange(boolean excludedEnd, long begin, long end) {
         this.end = end;
     }
 
+    public RubyLongRange(RubyLongRange other) {
+        this.excludedEnd = other.excludedEnd;
+        this.begin = other.begin;
+        this.end = other.end;
+    }
+
     @ExportMessage
     public boolean hasIterator() {
         return true;