Rollup merge of #134949 - compiler-errors:froms, r=jieyouxu

Convert some `Into` impls into `From` impls

From the [`From`](https://doc.rust-lang.org/std/convert/trait.From.html) docs:

> One should always prefer implementing `From` over [`Into`](https://doc.rust-lang.org/std/convert/trait.Into.html) because implementing `From` automatically provides one with an implementation of [`Into`](https://doc.rust-lang.org/std/convert/trait.Into.html) thanks to the blanket implementation in the standard library.
>
> Only implement [`Into`](https://doc.rust-lang.org/std/convert/trait.Into.html) when targeting a version prior to Rust 1.41 and converting to a type outside the current crate. `From` was not able to do these types of conversions in earlier versions because of Rust’s orphaning rules. See [Into](https://doc.rust-lang.org/std/convert/trait.Into.html) for more details.

Some of these impls are likely from before 1.41, and then some others were probably just mistakes. Building nightly rust is definitely not supported on 1.41, so let's modernize these impls :D

2 files changed, 6 insertions, 6 deletions

diff --git a/compiler/rustc_middle/src/mir/interpret/error.rs b/compiler/rustc_middle/src/mir/interpret/error.rs
index 37328470aa7..8c085fa310a 100644
--- a/compiler/rustc_middle/src/mir/interpret/error.rs
+++ b/compiler/rustc_middle/src/mir/interpret/error.rs
@@ -88,10 +88,10 @@ impl ReportedErrorInfo {
     }
 }
 
-impl Into<ErrorGuaranteed> for ReportedErrorInfo {
+impl From<ReportedErrorInfo> for ErrorGuaranteed {
     #[inline]
-    fn into(self) -> ErrorGuaranteed {
-        self.error
+    fn from(val: ReportedErrorInfo) -> Self {
+        val.error
     }
 }
 
diff --git a/compiler/rustc_middle/src/ty/adt.rs b/compiler/rustc_middle/src/ty/adt.rs
index 8f4137cc011..e28fcc555dc 100644
--- a/compiler/rustc_middle/src/ty/adt.rs
+++ b/compiler/rustc_middle/src/ty/adt.rs
@@ -249,9 +249,9 @@ pub enum AdtKind {
     Enum,
 }
 
-impl Into<DataTypeKind> for AdtKind {
-    fn into(self) -> DataTypeKind {
-        match self {
+impl From<AdtKind> for DataTypeKind {
+    fn from(val: AdtKind) -> Self {
+        match val {
             AdtKind::Struct => DataTypeKind::Struct,
             AdtKind::Union => DataTypeKind::Union,
             AdtKind::Enum => DataTypeKind::Enum,