[gcc r11-6555] Tweak dg-prune-output regex for out-of-build-tree contexts

[Olivier Hainque]

https://gcc.gnu.org/g:98546324c799c5c2d00491ab64e8dee3c3b0120e

commit r11-6555-g98546324c799c5c2d00491ab64e8dee3c3b0120e
Author: Olivier Hainque <hainque@adacore.com>
Date:   Fri Dec 18 18:09:21 2020 +0000

    Tweak dg-prune-output regex for out-of-build-tree contexts
    
    libstdc++-v3/
    
            * testsuite/20_util/bind/ref_neg.cc: Tweak the
            dg-prune-output regex for out-of-build-tree contexts.

Diff:
---
 libstdc++-v3/testsuite/20_util/bind/ref_neg.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/testsuite/20_util/bind/ref_neg.cc b/libstdc++-v3/testsuite/20_util/bind/ref_neg.cc
index 4645c9793a7..9cb9ed9c49e 100644
--- a/libstdc++-v3/testsuite/20_util/bind/ref_neg.cc
+++ b/libstdc++-v3/testsuite/20_util/bind/ref_neg.cc
@@ -49,7 +49,8 @@ void test02()
 }
 
 // Ignore the reasons for deduction/substitution failure in the headers.
-// { dg-prune-output "/include/(functional|bits/invoke.h):" }
+// Arrange for the match to work on installed trees as well as build trees.
+// { dg-prune-output "/(functional|bits/invoke.h):" }
 
 int main()
 {