Adding upstream version 1.65.7.

Signed-off-by: Daniel Baumann <daniel@debian.org>

testdata/memgrind/doublefree.c

@@ -0,0 +1,16 @@
+// This program frees allocated memory twice.
+//
+// Compile to Go: `$ ccgo -o main.go doublefree.c`.
+//
+// To run the resulting Go code: `$ go run main.go`.
+//
+// To run the resulting Go code with memgrind: `$ go run -tags=libc.memgrind main.go`.
+
+#include <stdlib.h>
+
+int main() {
+	void *p = malloc(42);
+	free(p);
+	free(p);
+}
+