patch 8.2.1157: Vim9: dict.name is not recognized as an expression

Problem:    Vim9: dict.name is not recognized as an expression.
Solution:   Recognize ".name". (closes #6418)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 59778eb..0573897 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3229,13 +3229,15 @@
 	// "varname[]" is an expression.
 	// "g:varname" is an expression.
 	// "varname->expr" is an expression.
+	// "varname.expr" is an expression.
 	// "(..." is an expression.
 	// "{..." is an dict expression.
 	if (*p == '('
 		|| *p == '{'
 		|| (*p == '[' && p > eap->cmd)
 		|| p[1] == ':'
-		|| (*p == '-' && p[1] == '>'))
+		|| (*p == '-' && p[1] == '>')
+		|| (*p == '.' && ASCII_ISALPHA(p[1])))
 	{
 	    eap->cmdidx = CMD_eval;
 	    return eap->cmd;