Fix up a couple more cases of incorrect sharing.

Author: aardvark179

src/main/java/org/truffleruby/core/array/ArrayNodes.java

@@ -150,7 +150,7 @@ protected RubyArray addGeneralize(RubyArray a, RubyArray b,
             final int aSize = aSizeProfile.profile(a.size);
             final int bSize = bSizeProfile.profile(b.size);
             final int combinedSize = aSize + bSize;
-            Object newStore = as.allocateForNewStore(aStore, bStore, combinedSize);
+            Object newStore = as.unsharedAllocateForNewStore(aStore, bStore, combinedSize);
             as.copyContents(aStore, 0, newStore, 0, aSize);
             bs.copyContents(bStore, 0, newStore, aSize, bSize);
             return createArray(newStore, combinedSize);
@@ -2345,7 +2345,7 @@ protected RubyArray zipToPairs(RubyArray array, RubyArray other,
             try {
                 for (; loopProfile.inject(n < zippedLength); n++) {
                     if (bNotSmallerProfile.profile(n < bSize)) {
-                        final Object pair = aStores.allocateForNewStore(a, b, 2);
+                        final Object pair = aStores.unsharedAllocateForNewStore(a, b, 2);
                         pairs.write(pair, 0, aStores.read(a, n));
                         pairs.write(pair, 1, bStores.read(b, n));
                         zipped[n] = createArray(pair, 2);

src/main/java/org/truffleruby/core/array/ArrayTruncateNode.java

@@ -50,8 +50,7 @@ protected void truncateCopy(RubyArray array, int size,
 
         final Object newStore = stores.allocateForNewStore(store, store, size);
         stores.copyContents(store, 0, newStore, 0, size);
-        array.store = newStore;
-        array.size = size;
+        ArrayHelpers.setStoreAndSize(array, newStore, size);
     }
 
     @ReportPolymorphism.Exclude

src/main/java/org/truffleruby/core/array/library/ArrayStoreLibrary.java

@@ -201,6 +201,12 @@ public void sort(Object store, int size) {
      * of {@code newStore}. */
     public abstract Object allocateForNewStore(Object store, Object newStore, int length);
 
+    /** Return a new store of length {@code length} that can accept all the values of {@code store} and all the values
+     * of {@code newStore} and is unshared. */
+    public Object unsharedAllocateForNewStore(Object store, Object newStore, int length) {
+        return allocateForNewStore(store, newStore, length);
+    }
+
     /** Return an allocator for a mutable version of {@code store}. */
     public abstract ArrayAllocator allocator(Object store);
 

src/main/java/org/truffleruby/core/array/library/SharedArrayStorage.java

@@ -251,6 +251,12 @@ protected Object allocateForNewStore(Object newStore, int length,
         return new SharedArrayStorage(stores.allocateForNewStore(storage, newStore, length));
     }
 
+    @ExportMessage
+    protected Object unsharedAllocateForNewStore(Object newStore, int length,
+            @CachedLibrary(limit = "1") ArrayStoreLibrary stores) {
+        return stores.allocateForNewStore(storage, newStore, length);
+    }
+
     @ExportMessage
     protected boolean isDefaultValue(Object value,
             @CachedLibrary(limit = "1") ArrayStoreLibrary stores) {