patch 8.2.2483: Vim9: type error for misformed expression

Problem:    Vim9: type error for misformed expression.
Solution:   Check for end of command before checking type. (closes #7795)
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 3c24fdb..7a220a8 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -6701,6 +6701,11 @@
 	clear_ppconst(&ppconst);
 	return NULL;
     }
+    if (!ends_excmd2(arg, skipwhite(p)))
+    {
+	semsg(_(e_trailing_arg), p);
+	return NULL;
+    }
     if (cctx->ctx_skip == SKIP_YES)
 	clear_ppconst(&ppconst);
     else if (instr->ga_len == instr_count && ppconst.pp_used == 1)
@@ -6825,6 +6830,11 @@
 	return NULL;
     }
     cctx->ctx_skip = save_skip;
+    if (!ends_excmd2(arg, skipwhite(p)))
+    {
+	semsg(_(e_trailing_arg), p);
+	return NULL;
+    }
     if (scope->se_skip_save == SKIP_YES)
 	clear_ppconst(&ppconst);
     else if (instr->ga_len == instr_count && ppconst.pp_used == 1)
@@ -7237,6 +7247,11 @@
     // compile "expr"
     if (compile_expr0(&p, cctx) == FAIL)
 	return NULL;
+    if (!ends_excmd2(arg, skipwhite(p)))
+    {
+	semsg(_(e_trailing_arg), p);
+	return NULL;
+    }
 
     if (bool_on_stack(cctx) == FAIL)
 	return FAIL;