Initial import of libdpf.

Co-authored-by: Cursor <cursoragent@cursor.com>

thirdparty/hedley/test/pure.c

@@ -0,0 +1,16 @@
+#include "../hedley.h"
+
+static int* b;
+
+HEDLEY_PURE
+static int taxi(int a) {
+  return
+    (a * a * a) +
+    (*b * *b * *b);
+}
+
+int main(void) {
+  *b = 10;
+
+  return taxi(9);
+}