Fix new tests

src/test/ui/feature-gate-if_while_or_patterns.stderr

@@ -20,3 +20,4 @@ error[E0658]: multiple patterns in `if let` and `while let` are unstable (see is
 
 error: aborting due to 2 previous errors
 
+If you want more information on this error, try using "rustc --explain E0658"

src/test/ui/impl_trait_projections.stderr

@@ -32,3 +32,5 @@ error[E0223]: ambiguous associated type
 
 error: aborting due to 5 previous errors
 
+You've got a few errors: E0223, E0667
+If you want more information on an error, try using "rustc --explain E0223"

src/test/ui/issue-23302-1.stderr

@@ -13,3 +13,4 @@ note: the cycle begins when const-evaluating `X::A::{{initializer}}`...
 
 error: aborting due to previous error
 
+If you want more information on this error, try using "rustc --explain E0391"

src/test/ui/issue-23302-2.stderr

@@ -13,3 +13,4 @@ note: the cycle begins when const-evaluating `Y::A::{{initializer}}`...
 
 error: aborting due to previous error
 
+If you want more information on this error, try using "rustc --explain E0391"

src/test/ui/issue-23302-3.stderr

@@ -18,3 +18,4 @@ note: ...which then requires processing `A`...
 
 error: aborting due to previous error
 
+If you want more information on this error, try using "rustc --explain E0391"

src/test/ui/issue-36163.stderr

@@ -18,4 +18,4 @@ note: ...which then requires const-evaluating `A`...
 
 error: aborting due to previous error
 
-If you want more information on this error, try using "rustc --explain E0265"
+If you want more information on this error, try using "rustc --explain E0391"

src/test/ui/issue-45157.stderr

@@ -18,3 +18,4 @@ error[E0502]: cannot borrow `u.s.a` as mutable because it is also borrowed as im
 
 error: aborting due to 2 previous errors
 
+If you want more information on this error, try using "rustc --explain E0502"

src/test/ui/issue-47706.stderr

@@ -28,5 +28,4 @@ note: required by `foo`
 
 error: aborting due to 2 previous errors
 
-You've got a few errors: E0593, E0601
-If you want more information on an error, try using "rustc --explain E0593"
+If you want more information on this error, try using "rustc --explain E0593"

src/test/ui/nested_impl_trait.stderr

@@ -48,3 +48,5 @@ error[E0562]: `impl Trait` not allowed outside of function and inherent method r
 
 error: aborting due to 6 previous errors
 
+You've got a few errors: E0562, E0666
+If you want more information on an error, try using "rustc --explain E0562"