Update OpenAL-soft to 1.21.1

libs/openal-soft/common/alstring.h

@@ -0,0 +1,30 @@
+#ifndef AL_STRING_H
+#define AL_STRING_H
+
+#include <cstddef>
+#include <cstring>
+#include <string>
+
+#include "almalloc.h"
+
+
+namespace al {
+
+template<typename T, typename Tr=std::char_traits<T>>
+using basic_string = std::basic_string<T, Tr, al::allocator<T>>;
+
+using string = basic_string<char>;
+using wstring = basic_string<wchar_t>;
+using u16string = basic_string<char16_t>;
+using u32string = basic_string<char32_t>;
+
+
+/* These would be better served by using a string_view-like span/view with
+ * case-insensitive char traits.
+ */
+int strcasecmp(const char *str0, const char *str1) noexcept;
+int strncasecmp(const char *str0, const char *str1, std::size_t len) noexcept;
+
+} // namespace al
+
+#endif /* AL_STRING_H */