Update TOML test suite (#661)

Ref #658

toml_testgen_test.go

@@ -1,4 +1,4 @@
-// Generated by tomltestgen for toml-test ref master on 2021-10-28T18:48:23-05:00
+// Generated by tomltestgen for toml-test ref master on 2021-11-08T22:33:24-05:00
 package toml_test
 
 import (
@@ -400,6 +400,11 @@ func TestTOMLTest_Invalid_InlineTable_DoubleComma(t *testing.T) {
 	testgenInvalid(t, input)
 }
 
+func TestTOMLTest_Invalid_InlineTable_DuplicateKey(t *testing.T) {
+	input := "# Duplicate keys within an inline table are invalid\na={b=1, b=2}\n"
+	testgenInvalid(t, input)
+}
+
 func TestTOMLTest_Invalid_InlineTable_Empty(t *testing.T) {
 	input := "t = {,}\n"
 	testgenInvalid(t, input)