Add regression tests for the impl_trait_in_bindings ICEs

Author: Alexendoo

src/test/ui/impl-trait/issues/issue-54600.rs

@@ -0,0 +1,7 @@
+use std::fmt::Debug;
+
+fn main() {
+    let x: Option<impl Debug> = Some(44_u32);
+    //~^ `impl Trait` not allowed outside of function and method return types
+    println!("{:?}", x);
+}

src/test/ui/impl-trait/issues/issue-54600.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-54600.rs:4:19
+   |
+LL |     let x: Option<impl Debug> = Some(44_u32);
+   |                   ^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-54840.rs

@@ -0,0 +1,7 @@
+use std::ops::Add;
+
+fn main() {
+    let i: i32 = 0;
+    let j: &impl Add = &i;
+    //~^ `impl Trait` not allowed outside of function and method return types
+}

src/test/ui/impl-trait/issues/issue-54840.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-54840.rs:5:13
+   |
+LL |     let j: &impl Add = &i;
+   |             ^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-58504.rs

@@ -0,0 +1,12 @@
+#![feature(generators, generator_trait, never_type)]
+
+use std::ops::Generator;
+
+fn mk_gen() -> impl Generator<Return=!, Yield=()> {
+    || { loop { yield; } }
+}
+
+fn main() {
+    let gens: [impl Generator<Return=!, Yield=()>;2] = [ mk_gen(), mk_gen() ];
+    //~^ `impl Trait` not allowed outside of function and method return types
+}

src/test/ui/impl-trait/issues/issue-58504.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-58504.rs:10:16
+   |
+LL |     let gens: [impl Generator<Return=!, Yield=()>;2] = [ mk_gen(), mk_gen() ];
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-58956.rs

@@ -0,0 +1,14 @@
+trait Lam {}
+
+pub struct B;
+impl Lam for B {}
+pub struct Wrap<T>(T);
+
+const _A: impl Lam = {
+    //~^ `impl Trait` not allowed outside of function and method return types
+    let x: Wrap<impl Lam> = Wrap(B);
+    //~^ `impl Trait` not allowed outside of function and method return types
+    x.0
+};
+
+fn main() {}

src/test/ui/impl-trait/issues/issue-58956.stderr

@@ -0,0 +1,15 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-58956.rs:7:11
+   |
+LL | const _A: impl Lam = {
+   |           ^^^^^^^^
+
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-58956.rs:9:17
+   |
+LL |     let x: Wrap<impl Lam> = Wrap(B);
+   |                 ^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0562`.

src/test/ui/impl-trait/issues/issue-70971.rs

@@ -0,0 +1,4 @@
+fn main() {
+    let x : (impl Copy,) = (true,);
+    //~^ `impl Trait` not allowed outside of function and method return types
+}

src/test/ui/impl-trait/issues/issue-70971.stderr

@@ -0,0 +1,9 @@
+error[E0562]: `impl Trait` not allowed outside of function and method return types
+  --> $DIR/issue-70971.rs:2:14
+   |
+LL |     let x : (impl Copy,) = (true,);
+   |              ^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0562`.