Commit d6b5dee42 failed to suppress that warning from MSVC,
so let's just get rid of all non-ASCII glyphs in the comments.
The comment for iso8859_1_to_ascii_upper[] is not essential,
and the other cases can be handled by spelling out the
Unicode character names.
(I'm now really in the dark as to why MSVC doesn't complain
about predicate.c's comment. But whatever.)
Discussion: https://postgr.es/m/1546512.1681495035@sss.pgh.pa.us
Buildfarm member hamerkop is unhappy that daitch_mokotoff.c "contains
a character that cannot be represented in the current code page
(932). Save the file in Unicode format to prevent data loss". There
are a lot of non-ASCII characters in comments, but I do not see any
outside a comment, so this is just cosmetic. Nonetheless the warning
is fairly scary and people might waste time trying to understand the
cause, so we ought to silence it.
We have only one other occurrence of a non-ASCII character in .c or .h
files in the tree: predicate.c mentions "Uwe Röhm". It's far from
clear why hamerkop isn't complaining about that too; but it isn't,
so maybe there is some special provision for accented Roman letters.
We can remove the non-letter symbols from the comment for
iso8859_1_to_ascii_upper without any real loss of usefulness,
so let's try that first to see if it silences the warning.
Discussion: https://postgr.es/m/1546512.1681495035@sss.pgh.pa.us
This modernized version of Soundex works significantly better than
the original, particularly for non-English names.
Dag Lem, reviewed by quite a few people along the way
Discussion: https://postgr.es/m/yger1atbgfy.fsf@sid.nimrod.no
Tom Lane