make suggestion stuff not swallow errors

The older code would sometimes swallow errors or fail to produce a
suggestion. The newer code does not. However, just printing everything
would produce a bunch of new and kind of annoying errors, so continue
to swallow `T: 'a` errors so long as there are other things to show.

src/test/compile-fail/issue-13058.rs

@@ -36,9 +36,5 @@ fn check<'r, I: Iterator<Item=usize>, T: Itble<'r, usize, I>>(cont: &T) -> bool
 fn main() {
     check((3, 5));
 //~^ ERROR mismatched types
-//~| expected `&_`
-//~| found `(_, _)`
-//~| expected &-ptr
-//~| found tuple
 //~| HELP run `rustc --explain E0308` to see a detailed explanation
 }

src/test/compile-fail/lifetime-inference-give-expl-lifetime-param-3.rs

@@ -22,7 +22,7 @@ fn bar1<'a>(x: &Bar) -> (&'a i32, &'a i32, &'a i32) {
 }
 
 fn bar2<'a, 'b, 'c>(x: &Bar<'a, 'b, 'c>) -> (&'a i32, &'a i32, &'a i32) {
-    //~^ HELP: consider using an explicit lifetime parameter as shown: fn bar2<'a, 'b, 'c>(x: &'a Bar<'a, 'b, 'c>) -> (&'a i32, &'a i32, &'a i32)
+    //~^ HELP: consider using an explicit lifetime parameter as shown: fn bar2<'a, 'c>(x: &'a Bar<'a, 'a, 'c>) -> (&'a i32, &'a i32, &'a i32)
     (x.bar, &x.baz, &x.baz)
     //~^ ERROR E0312
     //~| ERROR cannot infer

src/test/compile-fail/lifetime-inference-give-expl-lifetime-param.rs

@@ -39,6 +39,7 @@ struct Cat<'x, T> { cat: &'x isize, t: T }
 struct Dog<'y> { dog: &'y isize }
 
 fn cat2<'x, 'y>(x: Cat<'x, Dog<'y>>) -> &'x isize {
+    //~^ HELP consider using an explicit lifetime parameter as shown: fn cat2<'x>(x: Cat<'x, Dog<'x>>) -> &'x isize
     x.t.dog //~ ERROR E0312
 }
 
@@ -48,6 +49,7 @@ struct Baz<'x> {
 
 impl<'a> Baz<'a> {
     fn baz2<'b>(&self, x: &isize) -> (&'b isize, &'b isize) {
+        //~^ HELP consider using an explicit lifetime parameter as shown: fn baz2<'b>(&self, x: &'b isize) -> (&'a isize, &'a isize)
         (self.bar, x) //~ ERROR E0312
         //~^ ERROR E0312
     }