libstdc++: Fix std::basic_stracktrace to not assume allocators throw std::bad_alloc

The standard allows allocators to throw any kind of exception, not only
something that can be caught as std::bad_alloc. std::basic_stracktrace
was assuming std::bad_alloc.

libstdc++-v3/ChangeLog:

	* include/std/stacktrace (basic_stacktrace::_Impl::_M_allocate):
	Do not assume allocators only throw std::bad_alloc.

libstdc++-v3/include/std/stacktrace

@@ -560,7 +560,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	      if constexpr (is_same_v<allocator_type, allocator<value_type>>)
 		{
 		  // For std::allocator we use nothrow-new directly so we
-		  // don't need to handle bad_alloc exceptions.
+		  // don't need to handle exceptions from __alloc.allocate(n).
 		  auto __p = __detail::__get_temporary_buffer<value_type>(__n);
 		  if (__p == nullptr) [[unlikely]]
 		    return nullptr;
@@ -572,7 +572,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 		    {
 		      _M_frames = __alloc.allocate(__n);
 		    }
-		  __catch (const std::bad_alloc&)
+		  __catch (...)
 		    {
 		      return nullptr;
 		    }