Store the type of each GVN value

[cjgillot]

MIR is fully typed, so type information is an integral part of what defines a value. GVN currently tries to circumvent storing types, which creates all sorts of complexities.

This PR stores the type along with the enum Value when defining a value index. This allows to simplify a lot of code.

Fixes #128094
Fixes #135128

r? @ghost for perf

[cjgillot]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 2684875 with merge 0debe2b...

[bors]

☀️ Try build successful - checks-actions
Build commit: 0debe2b (0debe2b1f819bc0387b12f860b7de22201171ddc)

[Kobzol]

Note: this benchmark will be delayed a bit, because we just switched to a new benchmarking machine and I need to backfill stable benchmark results. Sorry for that! It should be done sometime tomorrow, hopefully.

[rust-timer]

Finished benchmarking commit (0debe2b): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

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

Max RSS (memory usage)

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

Cycles

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

Binary size

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

Bootstrap: missing data
Artifact size: 372.23 MiB -> 371.76 MiB (-0.13%)

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[cjgillot]

r? compiler