// (6,17): error CS0173: Type of conditional expression cannot be determined because there is no implicit conversion between 'stackalloc int[10]' and 'stackalloc int[5]'
// var x = true ? stackalloc int [10] : stackalloc int [5];
Diagnostic(ErrorCode.ERR_InvalidQM,"true ? stackalloc int [10] : stackalloc int [5]").WithArguments("stackalloc int[10]","stackalloc int[5]").WithLocation(6,17));