* patch by Sergey Larin: Reducing and aligning the size of TAnsiRec, TUnicodeRec for CPU64, resolves #38018:
    For CPU64, the size of record TAnsiRec and TUnicodeRec is 16 bytes instead of 24.
    Which is very good also because of the alignment. when allocating memory, the address
    of the first character of the string will be aligned on the 16-byte boundary.
    At the same time, the useless Dummy field, which is needed in CPU64 for exactly alignment, has been removed.
    For CPU32 (and CPU16), the record size has not changed, so procedures such as
    fpc_AnsiStr_Decr_Ref, implemented in assembler (see i386, arm), remained working correctly.
  * tests adapted