patch 8.2.0586: Vim9: # comment not sufficiently tested

Problem:    Vim9: # comment not sufficiently tested
Solution:   Check for preceding white space.
diff --git a/src/eval.c b/src/eval.c
index af22896..1840f74 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -6143,7 +6143,7 @@
 
     if (eap->skip)
 	++emsg_skip;
-    while (*arg != NUL && *arg != '|' && *arg != '\n')
+    while (!ends_excmd2(eap->cmd, arg) || *arg == '"')
     {
 	ret = eval1_emsg(&arg, &rettv, !eap->skip);
 	if (ret == FAIL)