0.3.0: converge relibc to upstream 0.6.0 + Red Bear patches

src/header/assert/cbindgen.toml

@@ -1,5 +1,24 @@
-sys_includes = ["bits/assert.h"]
+# POSIX header spec: https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/assert.h.html
+#
+# There are no spec quotations relating to includes
+#
+# features.h included for Rust never type (no return)
+sys_includes = ["features.h"]
 include_guard = "_RELIBC_ASSERT_H"
+# trailer is placed outside include_guard
+trailer = """
+// Do not use include guard, to ensure assert is always defined
+#ifdef assert
+#undef assert
+#endif
+
+#ifdef NDEBUG
+# define assert(cond) (void) 0
+#else
+# define assert(cond) \
+  ((void)((cond) || (__assert_fail(__func__, __FILE__, __LINE__, #cond), 0)))
+#endif
+"""
 language = "C"
 style = "Tag"
 no_includes = true