syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // by disparate pieces of the compiler, and keeping track of which files
context_before:     // cfg=output.txt --print link-args=output.txt`, because outputs are printed
context_after:     // need to be overwritten vs appended to is annoying.