Rollup merge of rust-lang#145057 - ShoyuVanilla:const-trait-tests-cleanup, r=petrochenkov

Clean up some resolved test regressions of const trait removals in std

cc rust-lang#143871

Author: Zalathar

coretests/tests/char.rs

@@ -21,7 +21,6 @@ fn test_convert() {
     assert!(char::try_from(0xFFFF_FFFF_u32).is_err());
 }
 
-/* FIXME(#110395)
 #[test]
 const fn test_convert_const() {
     assert!(u32::from('a') == 0x61);
@@ -31,7 +30,6 @@ const fn test_convert_const() {
     assert!(char::from(b'a') == 'a');
     assert!(char::from(b'\xFF') == '\u{FF}');
 }
-*/
 
 #[test]
 fn test_from_str() {

coretests/tests/convert.rs

@@ -1,4 +1,3 @@
-/* FIXME(#110395)
 #[test]
 fn convert() {
     const fn from(x: i32) -> i32 {
@@ -15,4 +14,3 @@ fn convert() {
     const BAR: Vec<String> = into(Vec::new());
     assert_eq!(BAR, Vec::<String>::new());
 }
-*/

coretests/tests/lib.rs

@@ -18,7 +18,9 @@
 #![feature(const_deref)]
 #![feature(const_destruct)]
 #![feature(const_eval_select)]
+#![feature(const_from)]
 #![feature(const_ops)]
+#![feature(const_option_ops)]
 #![feature(const_ref_cell)]
 #![feature(const_result_trait_fn)]
 #![feature(const_trait_impl)]

coretests/tests/nonzero.rs

@@ -214,13 +214,11 @@ fn nonzero_const() {
     const ONE: Option<NonZero<u8>> = NonZero::new(1);
     assert!(ONE.is_some());
 
-    /* FIXME(#110395)
     const FROM_NONZERO_U8: u8 = u8::from(NONZERO_U8);
     assert_eq!(FROM_NONZERO_U8, 5);
 
     const NONZERO_CONVERT: NonZero<u32> = NonZero::<u32>::from(NONZERO_U8);
     assert_eq!(NONZERO_CONVERT.get(), 5);
-    */
 }
 
 #[test]

coretests/tests/num/const_from.rs

@@ -1,4 +1,3 @@
-/* FIXME(#110395)
 #[test]
 fn from() {
     use core::convert::TryFrom;
@@ -24,4 +23,3 @@ fn from() {
     const I16_FROM_U16: Result<i16, TryFromIntError> = i16::try_from(1u16);
     assert_eq!(I16_FROM_U16, Ok(1i16));
 }
-*/

coretests/tests/option.rs

@@ -87,7 +87,6 @@ fn test_and() {
     assert_eq!(x.and(Some(2)), None);
     assert_eq!(x.and(None::<isize>), None);
 
-    /* FIXME(#110395)
     const FOO: Option<isize> = Some(1);
     const A: Option<isize> = FOO.and(Some(2));
     const B: Option<isize> = FOO.and(None);
@@ -99,7 +98,6 @@ fn test_and() {
     const D: Option<isize> = BAR.and(None);
     assert_eq!(C, None);
     assert_eq!(D, None);
-    */
 }
 
 #[test]