Implement realpath

src/header/limits/cbindgen.toml

@@ -0,0 +1,8 @@
+sys_includes = []
+include_guard = "_LIMITS_H"
+language = "C"
+style = "Tag"
+trailer = "#include <bits/limits.h>"
+
+[enum]
+prefix_with_name = true

src/header/limits/mod.rs

@@ -0,0 +1,3 @@
+//! limits.h implementation for relibc
+
+pub const PATH_MAX: usize = 4096;