fixup tests wrt new normalization

Author: WaffleLapkin

tests/ui/const-generics/nested-type.rs

@@ -3,7 +3,7 @@
 #![cfg_attr(full, feature(adt_const_params))]
 #![cfg_attr(full, allow(incomplete_features))]
 
-struct Foo<const N: [u8; { //[min]~ ERROR `[u8; _]` is forbidden
+struct Foo<const N: [u8; {
     struct Foo<const N: usize>;
 
     impl<const N: usize> Foo<N> {
@@ -15,5 +15,9 @@ struct Foo<const N: [u8; { //[min]~ ERROR `[u8; _]` is forbidden
     Foo::<17>::value()
     //~^ ERROR cannot call non-const fn
 }]>;
+//[min]~^^^^^^^^^^^^ ERROR `[u8; {
+
+// N.B. it is important that the comment above is not inside the array length,
+//      otherwise it may check for itself, instead of the actual error
 
 fn main() {}

tests/ui/fmt/format-string-error.rs

@@ -17,7 +17,7 @@ fn main() {
     let _ = format!("}");
     //~^ ERROR invalid format string: unmatched `}` found
     let _ = format!("{\\}");
-    //~^ ERROR invalid format string: expected `'}'`, found `'\\'`
+    //~^ ERROR invalid format string: expected `'}'`, found `'\'`
     let _ = format!("\n\n\n{\n\n\n");
     //~^ ERROR invalid format string
     let _ = format!(r###"

tests/ui/parser/issues/issue-62913.rs

@@ -1,4 +1,4 @@
 "\u\\"
 //~^ ERROR incorrect unicode escape sequence
 //~| ERROR invalid trailing slash in literal
-//~| ERROR expected item, found `"\u\\"`
+//~| ERROR expected item, found `"\u\"`