[runtime/heap] Introduce CopyFixedArrayUpTo to match CopyFixedArrayAndGrow, copying to a smaller ar…

src/heap/heap.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 1859 matching lines @@
   // Allocates an uninitialized fixed array. It must be filled by the caller.
   MUST_USE_RESULT AllocationResult AllocateUninitializedFixedArray(int length);
 
   // Make a copy of src and return it.
   MUST_USE_RESULT inline AllocationResult CopyFixedArray(FixedArray* src);
 
   // Make a copy of src, also grow the copy, and return the copy.
   MUST_USE_RESULT AllocationResult
   CopyFixedArrayAndGrow(FixedArray* src, int grow_by, PretenureFlag pretenure);
 
+  // Make a copy of src, also grow the copy, and return the copy.
+  MUST_USE_RESULT AllocationResult CopyFixedArrayUpTo(FixedArray* src,
+                                                      int new_len,
+                                                      PretenureFlag pretenure);
+
   // Make a copy of src, set the map, and return the copy.
   MUST_USE_RESULT AllocationResult
       CopyFixedArrayWithMap(FixedArray* src, Map* map);
 
   // Make a copy of src and return it.
   MUST_USE_RESULT inline AllocationResult CopyFixedDoubleArray(
       FixedDoubleArray* src);
 
   // Computes a single character string where the character has code.
   // A cache is used for one-byte (Latin1) codes.
@@ skipping 740 matching lines @@
 
  private:
   friend class NewSpace;
   DISALLOW_COPY_AND_ASSIGN(InlineAllocationObserver);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_