patch 8.2.0156: various typos in source files and tests

Problem:    Various typos in source files and tests.
Solution:   Fix the typos. (Emir Sari, closes #5532)
diff --git a/src/option.c b/src/option.c
index e24181a..f02dd26 100644
--- a/src/option.c
+++ b/src/option.c
@@ -3155,7 +3155,7 @@
 
 #if defined(FEAT_EVAL)
     // Save the global value before changing anything. This is needed as for
-    // a global-only option setting the "local value" infact sets the global
+    // a global-only option setting the "local value" in fact sets the global
     // value (since there is only one value).
     if ((opt_flags & (OPT_LOCAL | OPT_GLOBAL)) == 0)
 	old_global_value = *(long *)get_varp_scope(&(options[opt_idx]),