VM_Address cell = allocFast(isScalar, bytes, inGC);
VM_Address cell = allocFast(bytes, align, offset, inGC);
  public final VM_Address alloc(boolean isScalar, int bytes, boolean inGC)     throws VM_PragmaInline {    if (FRAGMENTATION_CHECK)      bytesAlloc += bytes;    VM_Address cell = allocFast(isScalar, bytes, inGC);    if (cell.isZero())       return allocSlow(isScalar, bytes, inGC);    else      return cell;  }