[pushed] libstdc++: avoid -Wzero-as-null-pointer-constant

[Jason Merrill]

Tested x86_64-pc-linux-gnu, applying to trunk as obvious.

-- 8< --

libstdc++-v3/ChangeLog:

        * include/std/coroutine (coroutine_handle): Use nullptr instead of
        0 as initializer for _M_fr_ptr.
---
 libstdc++-v3/include/std/coroutine | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/coroutine 
b/libstdc++-v3/include/std/coroutine
index 908c1178a14..ccd016b255e 100644
--- a/libstdc++-v3/include/std/coroutine
+++ b/libstdc++-v3/include/std/coroutine
@@ -99,7 +99,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
     public:
       // [coroutine.handle.con], construct/reset
-      constexpr coroutine_handle() noexcept : _M_fr_ptr(0) {}
+      constexpr coroutine_handle() noexcept : _M_fr_ptr(nullptr) {}
 
       constexpr coroutine_handle(std::nullptr_t __h) noexcept
        : _M_fr_ptr(__h)

base-commit: 7b500fa34ad88d5fdd4bf74eb2737b214749075b
-- 
2.46.0