Fixing:
- a raw `free()` in ECH code that's malloced in lib code, causing
an invalid free, also reported by valgrind (in non-unity builds).
And in unity builds adjusted to behave like non-unity via #17827:
Ref: https://github.com/curl/curl/actions/runs/
16093372427/job/
45421778472?pr=17827#step:39:3321
- a local pair of `malloc()`/`free()` to use curl's memory allocators,
and participate in memory tracking when enabled.
Cherry-picked from #17827
Closes #17830
#include "cipher_suite.h"
#include "x509asn1.h"
+/* The last #include files should be: */
+#include "../curl_memory.h"
+#include "../memdebug.h"
+
struct rustls_ssl_backend_data
{
const struct rustls_client_config *config;