Function checkGrammarForDisallowedTrailingComma

test/fixtures/snapshot/typescript.js:88029–88035

(list, diag)

            return grammarErrorOnNode(asyncModifier, ts.Diagnostics._0_modifier_cannot_be_used_here, "async");
        }
        function checkGrammarForDisallowedTrailingComma(list, diag) {
            if (diag === void 0) { diag = ts.Diagnostics.Trailing_comma_not_allowed; }
            if (list && list.hasTrailingComma) {
                return grammarErrorAtPos(list[0], list.end - ",".length, ",".length, diag);
            }
            return false;
        }
        function checkGrammarTypeParameterList(typeParameters, file) {
            if (typeParameters && typeParameters.length === 0) {
                var start = typeParameters.pos - "<".length;