refactor: restructure list/map compilation loops and extract syntax error tests

- Convert list() and map() compiler functions from if/do-while to do-while loops
- Remove redundant empty literal handling by breaking on right bracket/brace
- Add new test files for duplicate comma, duplicate trailing comma, and empty list/map with comma
- Expand newlines test to cover trailing comma and empty list/map cases
- Simplify trailing_comma tests by removing inline syntax error checks
- Update Test.fail() to handle variable arguments without kwargs

test/language/map/trailing_comma.wren

@@ -5,9 +5,3 @@ var map = {
 
 IO.print(map["a"]) // expect: 1
 IO.print(map["b"]) // expect: 2
-
-// Invalid syntax
-// Parentheses are necessary to have these interpret as maps and not as blocks.
-IO.print(new Fiber { Meta.eval("({,})")        }.try()) // expect: Could not compile source code.
-IO.print(new Fiber { Meta.eval("({1:1,,})")    }.try()) // expect: Could not compile source code.
-IO.print(new Fiber { Meta.eval("({1:1,,2:2})") }.try()) // expect: Could not compile source code.