libstdc++: Fix access error in __gnu_test::uneq_allocator

The operator== function is only a friend of the LHS argument, so cannot
access the private member of the RHS argument. Use the public accessor
instead.

libstdc++-v3/ChangeLog:

	* testsuite/util/testsuite_allocator.h (uneq_allocator): Fix
	equality operator for heterogeneous comparisons.

(cherry picked from commit 0585daf7de0673ade9feca1be66a68178786b48d)
1 file changed