Don't immediately error for recursive projections

Author: matthewjasper

compiler/rustc_error_codes/src/error_codes/E0284.md

@@ -14,7 +14,7 @@ fn main() {
 
 Here we have an addition of `d` and `n.into()`. Hence, `n.into()` can return
 any type `T` where `u64: Add<T>`. On the other hand, the `into` method can
-rteurn any type where `u32: Into<T>`.
+return any type where `u32: Into<T>`.
 
 The author of this code probably wants `into()` to return a `u64`, but the
 compiler can't be sure that there isn't another type `T` where both

src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.rs

@@ -24,7 +24,9 @@ impl<'a, 'b> Lam<&'a &'b u8> for L2 {
 
 trait Case1 {
     type C: Clone + Iterator<Item: Send + Iterator<Item: for<'a> Lam<&'a u8, App: Debug>> + Sync>;
-    //~^ ERROR overflow evaluating the requirement `<<Self as Case1>::C as std::iter::Iterator>::Item`
+    //~^ ERROR `<<Self as Case1>::C as std::iter::Iterator>::Item` is not an iterator
+    //~| ERROR `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be sent between threads safely
+    //~| ERROR `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be shared between threads safely
 }
 
 pub struct S1;

src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr

@@ -1,4 +1,4 @@
-error[E0275]: overflow evaluating the requirement `<<Self as Case1>::C as std::iter::Iterator>::Item`
+error[E0277]: `<<Self as Case1>::C as std::iter::Iterator>::Item` is not an iterator
   --> $DIR/bad-bounds-on-assoc-in-trait.rs:28:5
    |
 LL | /     type C: Clone + Iterator<Item:
@@ -49,6 +49,6 @@ help: consider further restricting the associated type
 LL | trait Case1 where <<Self as Case1>::C as std::iter::Iterator>::Item: std::marker::Sync {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0275`.
+For more information about this error, try `rustc --explain E0277`.

src/test/ui/associated-types/defaults-cyclic-fail-1.stderr

@@ -1,16 +1,15 @@
-error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-1.rs:26:5
    |
 LL |     type A = Box<Self::B>;
    |     ^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<usize as Tr>::A`
+error[E0271]: type mismatch resolving `<usize as Tr>::A == _`
   --> $DIR/defaults-cyclic-fail-1.rs:32:5
    |
 LL |     type B = &'static Self::A;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
 error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0271, E0275.
-For more information about an error, try `rustc --explain E0271`.
+For more information about this error, try `rustc --explain E0271`.

src/test/ui/associated-types/defaults-cyclic-fail-2.stderr

@@ -1,10 +1,10 @@
-error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
   --> $DIR/defaults-cyclic-fail-2.rs:27:5
    |
 LL |     type A = Box<Self::B>;
    |     ^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error[E0275]: overflow evaluating the requirement `<usize as Tr>::A`
+error[E0271]: type mismatch resolving `<usize as Tr>::A == _`
   --> $DIR/defaults-cyclic-fail-2.rs:33:5
    |
 LL |     type B = &'static Self::A;

src/test/ui/issues/issue-21946.stderr

@@ -1,4 +1,4 @@
-error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A`
+error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A == _`
   --> $DIR/issue-21946.rs:8:5
    |
 LL |     type A = <FooStruct as Foo>::A;

src/test/ui/issues/issue-23122-1.stderr

@@ -1,4 +1,4 @@
-error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next`
+error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next == _`
   --> $DIR/issue-23122-1.rs:8:5
    |
 LL |     type Next = <GetNext<T> as Next>::Next;