diff.txt: Update Vim 9.0.0701

Author: tsuyoshicho

en/diff.txt

@@ -1,4 +1,4 @@
-*diff.txt*      For Vim version 9.0.  Last change: 2022 Jan 22
+*diff.txt*      For Vim version 9.0.  Last change: 2022 Oct 01
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -376,6 +376,9 @@ Additionally, 'diffexpr' should take care of "icase" and "iwhite" in the
 'diffopt' option.  'diffexpr' cannot change the value of 'lines' and
 'columns'.
 
+The advantage of using a function call without arguments is that it is faster,
+see |expr-option-function|.
+
 Example (this does almost the same as 'diffexpr' being empty): >
 
 	set diffexpr=MyDiff()
@@ -441,6 +444,9 @@ will have the same effect.  These variables are set to the file names used:
 	v:fname_diff		patch file
 	v:fname_out		resulting patched file
 
+The advantage of using a function call without arguments is that it is faster,
+see |expr-option-function|.
+
 Example (this does the same as 'patchexpr' being empty): >
 
 	set patchexpr=MyPatch()