Update OpenAL-soft to 1.21.1

libs/openal-soft/common/opthelpers.h

@@ -0,0 +1,45 @@
+#ifndef OPTHELPERS_H
+#define OPTHELPERS_H
+
+#ifdef __has_builtin
+#define HAS_BUILTIN __has_builtin
+#else
+#define HAS_BUILTIN(x) (0)
+#endif
+
+#if defined(__GNUC__) || HAS_BUILTIN(__builtin_expect)
+/* LIKELY optimizes the case where the condition is true. The condition is not
+ * required to be true, but it can result in more optimal code for the true
+ * path at the expense of a less optimal false path.
+ */
+#define LIKELY(x) (__builtin_expect(!!(x), !false))
+/* The opposite of LIKELY, optimizing the case where the condition is false. */
+#define UNLIKELY(x) (__builtin_expect(!!(x), false))
+
+#else
+
+#define LIKELY(x) (!!(x))
+#define UNLIKELY(x) (!!(x))
+#endif
+
+#if HAS_BUILTIN(__builtin_assume)
+/* Unlike LIKELY, ASSUME requires the condition to be true or else it invokes
+ * undefined behavior. It's essentially an assert without actually checking the
+ * condition at run-time, allowing for stronger optimizations than LIKELY.
+ */
+#define ASSUME __builtin_assume
+#elif defined(_MSC_VER)
+#define ASSUME __assume
+#elif defined(__GNUC__)
+#define ASSUME(x) do { if(!(x)) __builtin_unreachable(); } while(0)
+#else
+#define ASSUME(x) ((void)0)
+#endif
+
+#if __cplusplus >= 201703L || defined(__cpp_if_constexpr)
+#define if_constexpr if constexpr
+#else
+#define if_constexpr if
+#endif
+
+#endif /* OPTHELPERS_H */