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/os_unix.c b/src/os_unix.c
index 5f2ece3..15d88f9 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -1931,7 +1931,7 @@
 	 * keep traversing up the tree until a window with a title/icon is
 	 * found.
 	 */
-	// Previously this was only done for xterm and alikes.  I don't see a
+	// Previously this was only done for xterm and alike.  I don't see a
 	// reason why it would fail for other terminal emulators.
 	// if (term_is_xterm)
 	{