vim-patch:9.0.0634: evaluating "expr" options has more overhead than needed

Problem:    Evaluating "expr" options has more overhead than needed.
Solution:   Use call_simple_func() for 'foldtext', 'includeexpr', 'printexpr',
            "expr" of 'spellsuggest', 'diffexpr', 'patchexpr', 'balloonexpr',
            'formatexpr', 'indentexpr' and 'charconvert'.

a4e0b9785e

vim-patch:9.0.0635: build error and compiler warnings

Problem:    Build error and compiler warnings.
Solution:   Add missing change.  Add type casts.

3292a22940

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/ex_docmd.c

@@ -4644,7 +4644,7 @@ static void ex_colorscheme(exarg_T *eap)
     char *expr = xstrdup("g:colors_name");
 
     emsg_off++;
-    char *p = eval_to_string(expr, false);
+    char *p = eval_to_string(expr, false, false);
     emsg_off--;
     xfree(expr);