eval.txt: Update Vim 9.0.0946

Author: tsuyoshicho

en/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 9.0.  Last change: 2022 Oct 07
+*eval.txt*	For Vim version 9.0.  Last change: 2022 Nov 22
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1548,7 +1548,7 @@ to be doubled.  These two commands are equivalent: >
 	if a =~ '\s*'
 
 
-interpolated-string				*$quote* *interp-string*
+interpolated-string				*$quote* *interpolated-string*
 --------------------
 $"string"		interpolated string constant		*expr-$quote*
 $'string'		interpolated literal string constant	*expr-$'*
@@ -2859,7 +2859,7 @@ text...
 			does not need to be doubled.
 			If "eval" is specified, then any Vim expression in the
 			form {expr} is evaluated and the result replaces the
-			expression, like with |interp-string|.
+			expression, like with |interpolated-string|.
 			Example where $HOME is expanded: >
 				let lines =<< trim eval END
 				  some text
@@ -3073,6 +3073,10 @@ text...
 			Unlock the internal variable {name}.  Does the
 			opposite of |:lockvar|.
 
+			If {name} does not exist:
+			- In |Vim9| script an error is given.
+			- In legacy script this is silently ignored.
+
 :if {expr1}			*:if* *:end* *:endif* *:en* *E171* *E579* *E580*
 :en[dif]		Execute the commands until the next matching `:else`
 			or `:endif` if {expr1} evaluates to non-zero.