Bump regalloc2 to 0.7.0 (#6237)

* Bump RA2 to 0.7.0

* Certify the RA2 update

* Import the rustc-hash audit

* Updates for regalloc2

prtest:full

* Update tests

winch/codegen/Cargo.toml

@@ -17,7 +17,7 @@ target-lexicon = { workspace = true, features = ["std"] }
 # In the next iteration we'll factor out the common bits so that they can be consumed
 # by Cranelift and Winch.
 cranelift-codegen = { workspace = true }
-regalloc2 = "0.6.0"
+regalloc2 = "0.7.0"
 gimli = { workspace = true }
 
 [features]