vim-patch:9.1.0700: crash with 2byte encoding and glob2regpat()

Problem:  possible crash with 2byte encoding and glob2regpat()
Solution: Skip over character, if it is multi-byte character

https://github.com/vim/vim/commit/1c815b54bbaf872c271d58043e51e56b908c1a20

Co-authored-by: Christian Brabandt <cb@256bit.org>

src/nvim/fileio.c

@@ -3754,7 +3754,6 @@ char *file_pat_to_reg_pat(const char *pat, const char *pat_end, char *allow_dirs
           *allow_dirs = true;
         }
         reg_pat[i++] = '\\';
-        reg_pat[i++] = *p;
       }
       break;
 #ifdef BACKSLASH_IN_FILENAME

test/old/testdir/test_crash.vim

@@ -226,6 +226,12 @@ func Test_crash1_3()
   call term_sendkeys(buf, args)
   call TermWait(buf, 150)
 
+  let file = 'crash/heap_overflow_glob2regpat'
+  let cmn_args = "%s -u NONE -i NONE -n -X -m -n -e -s -S %s -c ':qa!'"
+  let args = printf(cmn_args, vim, file)
+  call term_sendkeys(buf, args)
+  call TermWait(buf, 50)
+
 
   " clean up
   exe buf .. "bw!"