Auto merge of #110027 - nbdd0121:dieting, r=m-ou-se

Add `#[inline]` to functions that are never called

This makes libcore binary size reduce by ~300 bytes. Not much, but these functions are never called so it doesn't make sense for them to get into the binary anyway.

Author: bors

Diff for: library/core/src/cmp.rs

@@ -1412,6 +1412,7 @@ mod impls {
 
     #[unstable(feature = "never_type", issue = "35121")]
     impl PartialEq for ! {
+        #[inline]
         fn eq(&self, _: &!) -> bool {
             *self
         }
@@ -1422,13 +1423,15 @@ mod impls {
 
     #[unstable(feature = "never_type", issue = "35121")]
     impl PartialOrd for ! {
+        #[inline]
         fn partial_cmp(&self, _: &!) -> Option<Ordering> {
             *self
         }
     }
 
     #[unstable(feature = "never_type", issue = "35121")]
     impl Ord for ! {
+        #[inline]
         fn cmp(&self, _: &!) -> Ordering {
             *self
         }

Diff for: library/core/src/convert/mod.rs

@@ -915,6 +915,7 @@ impl Ord for Infallible {
 
 #[stable(feature = "convert_infallible", since = "1.34.0")]
 impl From<!> for Infallible {
+    #[inline]
     fn from(x: !) -> Self {
         x
     }

Diff for: library/core/src/fmt/mod.rs

@@ -2267,13 +2267,15 @@ fmt_refs! { Debug, Display, Octal, Binary, LowerHex, UpperHex, LowerExp, UpperEx
 
 #[unstable(feature = "never_type", issue = "35121")]
 impl Debug for ! {
+    #[inline]
     fn fmt(&self, _: &mut Formatter<'_>) -> Result {
         *self
     }
 }
 
 #[unstable(feature = "never_type", issue = "35121")]
 impl Display for ! {
+    #[inline]
     fn fmt(&self, _: &mut Formatter<'_>) -> Result {
         *self
     }

Diff for: library/core/src/intrinsics.rs

@@ -2523,6 +2523,7 @@ macro_rules! assert_unsafe_precondition {
                 }
             }
             #[allow(non_snake_case)]
+            #[inline]
             const fn comptime$(<$($tt)*>)?($(_:$ty),*) {}
 
             ::core::intrinsics::const_eval_select(($($i,)*), comptime, runtime);

Diff for: library/core/src/intrinsics/mir.rs

@@ -263,6 +263,7 @@ pub struct BasicBlock;
 macro_rules! define {
     ($name:literal, $( #[ $meta:meta ] )* fn $($sig:tt)*) => {
         #[rustc_diagnostic_item = $name]
+        #[inline]
         $( #[ $meta ] )*
         pub fn $($sig)* { panic!() }
     }

Diff for: library/core/src/num/error.rs

@@ -34,6 +34,7 @@ impl From<Infallible> for TryFromIntError {
 
 #[unstable(feature = "never_type", issue = "35121")]
 impl From<!> for TryFromIntError {
+    #[inline]
     fn from(never: !) -> TryFromIntError {
         // Match rather than coerce to make sure that code like
         // `From<Infallible> for TryFromIntError` above will keep working