tests: update some compile-fail tests for the new behavior of type expectations.

Author: eddyb

src/test/compile-fail/issue-15783.rs

@@ -14,7 +14,8 @@ pub fn foo(params: Option<&[&str]>) -> usize {
 
 fn main() {
     let name = "Foo";
-    let msg = foo(Some(&[name.as_slice()]));
+    let x = Some(&[name.as_slice()]);
+    let msg = foo(x);
 //~^ ERROR mismatched types: expected `core::option::Option<&[&str]>`
     assert_eq!(msg, 3);
 }

src/test/compile-fail/regions-early-bound-error-method.rs

@@ -28,6 +28,8 @@ impl<'a> GetRef<'a> for Box<'a> {
 impl<'a> Box<'a> {
     fn or<'b,G:GetRef<'b>>(&self, g2: G) -> &'a isize {
         g2.get() //~ ERROR cannot infer an appropriate lifetime for automatic coercion due to
+        //~^ ERROR mismatched types: expected `&'a isize`, found `&'b isize` (lifetime mismatch)
+
     }
 }
 

src/test/compile-fail/regions-early-bound-error.rs

@@ -27,6 +27,7 @@ impl<'a,T:Clone> GetRef<'a,T> for Box<'a,T> {
 
 fn get<'a,'b,G:GetRef<'a, isize>>(g1: G, b: &'b isize) -> &'b isize {
     g1.get() //~ ERROR cannot infer an appropriate lifetime for automatic coercion due to
+    //~^ ERROR mismatched types: expected `&'b isize`, found `&'a isize` (lifetime mismatch)
 }
 
 fn main() {