Issue #25677: Correct syntax error caret for indented blocks.

Based on patch by Michael Layzell.
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 72b6c9b..90cb2de 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -528,7 +528,7 @@
             offset -= (int)(nl+1-text);
             text = nl+1;
         }
-        while (*text == ' ' || *text == '\t') {
+        while (*text == ' ' || *text == '\t' || *text == '\f') {
             text++;
             offset--;
         }