Upgrade to regalloc2 v0.2.3 to get bugfix from bytecodealliance/regalloc2#60. (#4335)

* Upgrade to regalloc2 v0.2.3 to get bugfix from bytecodealliance/regalloc2#60.

* Update RELEASES.md.

* Update two compile tests based on slightly shifting regalloc output.

Cargo.lock

@@ -2352,9 +2352,9 @@ dependencies = [
 
 [[package]]
 name = "regalloc2"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d37148700dbb38f994cd99a1431613057f37ed934d7e4d799b7ab758c482461"
+checksum = "4a8d23b35d7177df3b9d31ed8a9ab4bf625c668be77a319d4f5efd4a5257701c"
 dependencies = [
  "fxhash",
  "log",