Stable MIR: Add basic MIR body datastructures

[oli-obk]

At this point it will panic on most useful MIR, but you can do basic assignments

r? @pnkfelix

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @pnkfelix (or someone else) soon.

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[rustbot]

This PR changes Stable MIR

cc @oli-obk, @celinval

[pnkfelix]

@bors r+

[bors]

📌 Commit 480e042 has been approved by pnkfelix

It is now in the queue for this repository.

[bors]

⌛ Testing commit 480e042 with merge 82bfda8...

[bors]

☀️ Test successful - checks-actions
Approved by: pnkfelix
Pushing 82bfda8 to master...

[bors]

☀️ Test successful - checks-actions
Approved by: pnkfelix
Pushing 82bfda8 to master...

[rust-timer]

Finished benchmarking commit (82bfda8): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.6%	[2.6%, 2.6%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.3%	[-3.3%, -3.3%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.3%	[-3.3%, 2.6%]	2

Cycles

This benchmark run did not return any relevant results for this metric.