Only print parameters with elided lifetimes in elision error messages.

When displaying the function parameters for a lifetime elision error message,
this changes it to first filter out the parameters that don't have elided
lifetimes.

Fixes #30255.

src/test/compile-fail/issue-30255.rs

@@ -0,0 +1,35 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+//
+// Test that lifetime elision error messages correctly omit parameters
+// with no elided lifetimes
+
+struct S<'a> {
+    field: &'a i32,
+}
+
+fn f(a: &S, b: i32) -> &i32 {
+//~^ ERROR missing lifetime specifier [E0106]
+//~^^ HELP does not say which one of `a`'s 2 elided lifetimes it is borrowed from
+    panic!();
+}
+
+fn g(a: &S, b: bool, c: &i32) -> &i32 {
+//~^ ERROR missing lifetime specifier [E0106]
+//~^^ HELP does not say whether it is borrowed from one of `a`'s 2 elided lifetimes or `c`
+    panic!();
+}
+
+fn h(a: &bool, b: bool, c: &S, d: &i32) -> &i32 {
+//~^ ERROR missing lifetime specifier [E0106]
+//~^^ HELP does not say whether it is borrowed from `a`, one of `c`'s 2 elided lifetimes, or `d`
+    panic!();
+}
+