[gcc(refs/vendors/ibm/heads/perf)] libstdc++: Fix test failure due to -Wnonnull warnings

[Jiu Fu Guo]

https://gcc.gnu.org/g:fcc443b97e19d9c8a2d8ccdfa4cc20682165827e

commit fcc443b97e19d9c8a2d8ccdfa4cc20682165827e
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Mar 12 11:03:04 2020 +0000

    libstdc++: Fix test failure due to -Wnonnull warnings
    
    This test fails in the Fedora RPM build (but not elsewhere, for unknown
    reasons). The warning is correct, we're passing a null pointer.
    
            * testsuite/tr1/8_c_compatibility/cstdlib/functions.cc: Do not pass
            a null pointer to functions with nonnull(1) attribute.

Diff:
---
 libstdc++-v3/ChangeLog                                            | 5 +++++
 libstdc++-v3/testsuite/tr1/8_c_compatibility/cstdlib/functions.cc | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 4ff4a0eecc9..5cf329fdda7 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2020-03-12  Jonathan Wakely  <jwakely@redhat.com>
+
+	* testsuite/tr1/8_c_compatibility/cstdlib/functions.cc: Do not pass
+	a null pointer to functions with nonnull(1) attribute.
+
 2020-03-11  Patrick Palka  <ppalka@redhat.com>
 
 	* include/std/ranges (split_view::_OuterIter::_OuterIter): Typo fix,
diff --git a/libstdc++-v3/testsuite/tr1/8_c_compatibility/cstdlib/functions.cc b/libstdc++-v3/testsuite/tr1/8_c_compatibility/cstdlib/functions.cc
index 89c078ffe6f..227a7580bcf 100644
--- a/libstdc++-v3/testsuite/tr1/8_c_compatibility/cstdlib/functions.cc
+++ b/libstdc++-v3/testsuite/tr1/8_c_compatibility/cstdlib/functions.cc
@@ -30,7 +30,7 @@ void test01()
 #if _GLIBCXX_USE_C99_STDLIB
 
   long long i = 0;
-  const char* s = 0;
+  const char* s = "";
   char** endptr = 0;
   int base = 0;