Trailing:
pub const SourceLocation = struct
pub const SourceLocation = struct {
src_path: String,
line: u32,
column: u32,
/// byte offset of starting token
span_start: u32,
/// byte offset of main error location
span_main: u32,
/// byte offset of end of last token
span_end: u32,
/// Does not include the trailing newline.
source_line: OptionalString = 0,
reference_trace_len: u32 = 0,
}