patch 8.1.1807: more functions can be used as a method

Problem:    More functions can be used as a method.
Solution:   Add append(), appendbufline(), assert_equal(), etc.
            Also add the :eval command.
diff --git a/runtime/doc/testing.txt b/runtime/doc/testing.txt
index 6fe6b8e..b51a1e1 100644
--- a/runtime/doc/testing.txt
+++ b/runtime/doc/testing.txt
@@ -1,4 +1,4 @@
-*testing.txt*	For Vim version 8.1.  Last change: 2019 Jul 28
+*testing.txt*	For Vim version 8.1.  Last change: 2019 Aug 04
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -222,7 +222,11 @@
 <		Will result in a string to be added to |v:errors|:
 	test.vim line 12: Expected 'foo' but got 'bar' ~
 
-							*assert_equalfile()*
+		Can also be used as a |method|: >
+			mylist->assert_equal([1, 2, 3])
+
+
+<							*assert_equalfile()*
 assert_equalfile({fname-one}, {fname-two})
 		When the files {fname-one} and {fname-two} do not contain
 		exactly the same text an error message is added to |v:errors|.
@@ -294,7 +298,10 @@
 		|v:errors| when {expected} and {actual} are equal.
 		Also see |assert-return|.
 
-							*assert_notmatch()*
+		Can also be used as a |method|: >
+			mylist->assert_notequal([1, 2, 3])
+
+<							*assert_notmatch()*
 assert_notmatch({pattern}, {actual} [, {msg}])
 		The opposite of `assert_match()`: add an error message to
 		|v:errors| when {pattern} matches {actual}.