In the code, test, and docs, because it makes it much easier to find
things.
Other than adding the comments about alphabetical order, this commit
only moves things around.
This lets us specify the default at the options declaration point,
instead of using `.unwrap(default)` or `None | Some(default)` at some
use point far away. It also makes the code more concise.
Add `-Z dump-mir-dataflow` flag for dumping dataflow results visualization
Previously, to visualize the results of a MIR dataflow pass, one had to add a `#[rustc_mir(borrowck_graphviz_postflow)]` attribute to functions of interest. However, there is no way to specify this attribute on closures and generators, so it was impossible to view results for these MIR bodies.
This PR adds a flag, `-Z dump-mir-dataflow`, which will output the dataflow results for any functions specified in `-Z dump-mir` to the output directory specified by `-Z dump-mir-dir`. This behavior is modeled on the `-Z dump-mir-graphviz` flag.
Specifically, remove both `-Z no_integrated_as` and
`TargetOptions::no_integrated_as`. The latter was only used for the
`msp430_none_elf` platform, for which it's no longer required.
`-C incremental` was introduced over two years ago. `-Z incremental` was
kept for transitioning, but it's been long enough now that it should be
ok to remove it.
