patch 9.0.0138: not enough characters accepted for 'spellfile'
Problem: Not enough characters accepted for 'spellfile'.
Solution: Add vim_is_fname_char() and use it for 'spellfile'.
diff --git a/src/proto/charset.pro b/src/proto/charset.pro
index 97aa71e..ebb548a 100644
--- a/src/proto/charset.pro
+++ b/src/proto/charset.pro
@@ -25,6 +25,7 @@
int vim_iswordp(char_u *p);
int vim_iswordp_buf(char_u *p, buf_T *buf);
int vim_isfilec(int c);
+int vim_is_fname_char(int c);
int vim_isfilec_or_wc(int c);
int vim_isprintc(int c);
int vim_isprintc_strict(int c);