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/testdir/test_breakindent.vim b/src/testdir/test_breakindent.vim
index f7cfb4e..6e4e090 100644
--- a/src/testdir/test_breakindent.vim
+++ b/src/testdir/test_breakindent.vim
@@ -1,7 +1,7 @@
 " Test for breakindent
 "
 " Note: if you get strange failures when adding new tests, it might be that
-" while the test is run, the breakindent cacheing gets in its way.
+" while the test is run, the breakindent caching gets in its way.
 " It helps to change the tabstop setting and force a redraw (e.g. see
 " Test_breakindent08())
 source check.vim