vim-patch:8.2.1361: error for white space after expression in assignment

Problem:    Error for white space after expression in assignment.
Solution:   Skip over white space. (closes vim/vim#6617)
6a25026262

src/nvim/eval.c

@@ -2086,6 +2086,7 @@ char_u *get_lval(char_u *const name, typval_T *const rettv,
           tv_clear(&var1);
           return NULL;
         }
+        p = skipwhite(p);
       }
 
       // Optionally get the second index [ :expr].

src/nvim/testdir/test_expr.vim

@@ -49,6 +49,9 @@ func Test_dict()
   let d['a'] = 'aaa'
   call assert_equal('none', d[''])
   call assert_equal('aaa', d['a'])
+
+  let d[ 'b' ] = 'bbb'
+  call assert_equal('bbb', d[ 'b' ])
 endfunc
 
 func Test_strgetchar()