[committed] libstdc++: Do not use nullptr in C++03-compatible code

[Jonathan Wakely via Gcc-patches]

Tested x86_64-linux, pushed to trunk.

-- >8 --

This has to be valid as C++98/C++03.

libstdc++-v3/ChangeLog:

        * include/debug/formatter.h [_GLIBCXX_DEBUG_BACKTRACE]
        (_Error_formatter): Use 0 as null pointer constant.
---
 libstdc++-v3/include/debug/formatter.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/debug/formatter.h 
b/libstdc++-v3/include/debug/formatter.h
index b4b72383e22..f120163c6d4 100644
--- a/libstdc++-v3/include/debug/formatter.h
+++ b/libstdc++-v3/include/debug/formatter.h
@@ -609,8 +609,7 @@ namespace __gnu_debug
     , _M_function(__function)
 #if _GLIBCXX_HAVE_STACKTRACE
 # ifdef _GLIBCXX_DEBUG_BACKTRACE
-    , _M_backtrace_state(
-      __glibcxx_backtrace_create_state(nullptr, 0, nullptr, nullptr))
+    , _M_backtrace_state(__glibcxx_backtrace_create_state(0, 0, 0, 0))
     , _M_backtrace_full(&__glibcxx_backtrace_full)
 # else
     , _M_backtrace_state()
-- 
2.37.3