Masamichi-san,
your fix for gs works fine; the resulting PDFs are small again. Thanks a lot! BUT: They are not as small as previously. For example, with commit 21a20de3, the NR has 10 pages more and is now 8.3MByte (I've tested compilation with both gs 9.21 and 9.52) instead of 7.1MByte (with gs 9.21, produced April 20th using commit f86f7705). As far as I can see, my used xetex binary is the same, as is `texinfo.tex` (version 2019-02-16.14), and the included fonts. Do you have any explanation for this? Is this expected, probably a side effect of your latest changes? I uncompressed the PDFs using `pdftk` and did a comparison; unfortunately I couldn't see big differences in the diff file, which probably hints at small but many changes that accumulate to the 15% difference. Werner