"input" data, i.e. pieces of immutable data that were computed before the
context was created and that queries can access to do their computations.
-As of <!-- date: 2021-01 --> January 2021, this input data consists mainly of
+As of <!-- date-check --> January 2021, this input data consists mainly of
the HIR map, upstream crate metadata, and the command-line options the compiler
was invoked with; but in the future inputs will just consist of command-line
options and a list of source files -- the HIR map will itself be provided by a