Some const_trait_impl test cleanups

tests/ui/traits/const-traits/const-drop.rs

@@ -17,12 +17,10 @@ impl<'a> const Drop for S<'a> {
 }
 
 const fn a<T: [const] Destruct>(_: T) {}
-//FIXME ~^ ERROR destructor of
 
 const fn b() -> u8 {
     let mut c = 0;
     let _ = S(&mut c);
-    //FIXME ~^ ERROR destructor of
     a(S(&mut c));
     c
 }

tests/ui/traits/const-traits/issue-102985.rs

@@ -1,12 +1,9 @@
-//@ known-bug: #110395
 #![feature(const_trait_impl)]
 
 struct Bug {
     inner: [(); match || 1 {
         n => n(),
-        //FIXME ~^ ERROR the trait bound
-        //FIXME ~| ERROR the trait bound
-        //FIXME ~| ERROR cannot call non-const closure in constants
+        //~^ ERROR cannot call non-const closure in constants
     }],
 }
 

tests/ui/traits/const-traits/issue-102985.stderr

@@ -1,5 +1,5 @@
 error[E0015]: cannot call non-const closure in constants
-  --> $DIR/issue-102985.rs:6:14
+  --> $DIR/issue-102985.rs:5:14
    |
 LL |         n => n(),
    |              ^^^

tests/ui/traits/const-traits/issue-88155.rs

@@ -1,5 +1,3 @@
-//@ known-bug: #110395
-
 #![feature(const_trait_impl)]
 
 pub trait A {
@@ -8,8 +6,7 @@ pub trait A {
 
 pub const fn foo<T: A>() -> bool {
     T::assoc()
-    //FIXME ~^ ERROR the trait bound
-    //FIXME ~| ERROR cannot call non-const function
+    //~^ ERROR cannot call non-const associated function
 }
 
 fn main() {}

tests/ui/traits/const-traits/issue-88155.stderr

@@ -1,5 +1,5 @@
 error[E0015]: cannot call non-const associated function `<T as A>::assoc` in constant functions
-  --> $DIR/issue-88155.rs:10:5
+  --> $DIR/issue-88155.rs:8:5
    |
 LL |     T::assoc()
    |     ^^^^^^^^^^