patch 8.2.0484: Vim9: some error messages not tested

Problem:    Vim9: some error messages not tested.
Solution:   Add more tests.

src/testdir/test_vim9_expr.vim

@@ -522,6 +522,7 @@ func Test_expr5_fails()
   call CheckDefFailure("let x = 33 + 0z1122", 'E1035')
   call CheckDefFailure("let x = [3] + 0z1122", 'E1035')
   call CheckDefFailure("let x = 'asdf' + 0z1122", 'E1035')
+  call CheckDefFailure("let x = 6 + xxx", 'E1001')
 endfunc
 
 " test multiply, divide, modulo
@@ -553,6 +554,8 @@ def Test_expr6()
     assert_equal(5.0, xf[0] + yf[0])
     assert_equal(6.0, xf[0] * yf[0])
   endif
+
+  call CheckDefFailure("let x = 6 * xxx", 'E1001')
 enddef
 
 def Test_expr6_float()
@@ -680,6 +683,8 @@ def Test_expr7_blob()
   assert_equal(g:blob_empty, 0z)
   assert_equal(g:blob_one, 0z01)
   assert_equal(g:blob_long, 0z0102.0304)
+
+  call CheckDefFailure("let x = 0z123", 'E973:')
 enddef
 
 def Test_expr7_string()
@@ -691,6 +696,9 @@ def Test_expr7_string()
   assert_equal(g:string_long, 'abcdefghijklm')
   assert_equal(g:string_long, "abcdefghijklm")
   assert_equal(g:string_special, "ab\ncd\ref\ekk")
+
+  call CheckDefFailure('let x = "abc', 'E114:')
+  call CheckDefFailure("let x = 'abc", 'E115:')
 enddef
 
 def Test_expr7_special()
@@ -738,6 +746,7 @@ def Test_expr7_dict()
   call CheckDefFailure("let x = {'a': xxx}", 'E1001:')
   call CheckDefFailure("let x = {xxx: 8}", 'E1001:')
   call CheckDefFailure("let x = #{a: 1, a: 2}", 'E721:')
+  call CheckDefFailure("let x = #", 'E1015:')
   call CheckDefFailure("let x += 1", 'E1020:')
   call CheckDefFailure("let x = x + 1", 'E1001:')
   call CheckDefExecFailure("let x = g:anint.member", 'E715:')

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    484,
 /**/
     483,
 /**/