Stop signaling an error when reading "smart quotes" in symbols

Revert commits from 2018-01-28 "Fix round tripping of read->print for
symbols with strange quotes", and 2017-07-22 "Signal error for symbol
names with strange quotes (Bug#2967)".
* etc/NEWS: Remove corresponding entries.
* src/character.c (confusable_symbol_character_p):
* test/src/lread-tests.el (lread-tests--old-style-backquotes): Remove.
* src/lread.c (read1): Don't signal error on confusable character.
* src/print.c (print_object): Don't escape confusable characters.

1 files changed, 0 insertions, 7 deletions

diff --git a/src/lread.c b/src/lread.c
index 4ea62029727..e5a9c93c55e 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -3571,13 +3571,6 @@ read1 (Lisp_Object readcharfun, int *pch, bool first_in_list)
             if (! NILP (result) && len == nbytes)
               return unbind_to (count, result);
           }
-        if (!quoted && multibyte)
-          {
-            int ch = STRING_CHAR ((unsigned char *) read_buffer);
-            if (confusable_symbol_character_p (ch))
-              xsignal2 (Qinvalid_read_syntax, build_string ("strange quote"),
-                        CALLN (Fstring, make_fixnum (ch)));
-          }
         {
           Lisp_Object result;
           ptrdiff_t nchars