Simplify templates

tests/native_type_test.fbs

@@ -24,12 +24,12 @@ table Matrix (native_type:"Native::Matrix") {
 // field via `native_type_template_arg` instead of needing one flatbuffers
 // struct declaration per specialization (compare to Vector3D/Vector3DAlt
 // above).
-struct Tagged (native_type_template: "Native::Tagged<{{T}}>") {
+struct Tagged (native_type_template: "Native::Tagged") {
   value:int32;
 }
 
 // A native type template that takes more than one argument.
-struct Pair (native_type_template: "Native::Pair<{{T0}}, {{T1}}>") {
+struct Pair (native_type_template: "Native::Pair") {
   value:int32;
 }
 

tests/parser_test.cpp

@@ -106,14 +106,6 @@ void ErrorTest() {
       "struct-typed fields");
   TestError(
       "struct X (native_type_template: \"Foo\") { Y:int; } "
-      "table T { y:X (native_type_template_arg:\"int\"); }",
-      "does not reference");
-  TestError(
-      "struct X (native_type_template: \"Foo<{{T0}}, {{T1}}>\") { Y:int; } "
-      "table T { y:X (native_type_template_arg:\"int\"); }",
-      "beyond the");
-  TestError(
-      "struct X (native_type_template: \"Foo<{{T}}>\") { Y:int; } "
       "table T { y:X (native_type_template_arg:\"\"); }",
       "empty template argument");
   TestError("{}", "no root");