The new pattern in the dg-prune-output directive doesn't work. Instead
of a messy regex full of leaning toothpicks, just match on the
diagnostic text instead of the header paths.
libstdc++-v3/ChangeLog:
* testsuite/20_util/bind/ref_neg.cc: Fix dg-prune-output
directive.
// Ignore the reasons for deduction/substitution failure in the headers.
// Arrange for the match to work on installed trees as well as build trees.
-// { dg-prune-output "[/\\](functional|bits/invoke.h):" }
+// { dg-prune-output "no type named 'type' in 'struct std::result_of" }
int main()
{