snooper: complete general dynamic and local exec TLS mode support

Signed-off-by: Andrii Nakryiko <[email protected]>

Author: anakryiko

examples/c/app.c

@@ -98,7 +98,9 @@ static void *thread_func(void *arg)
 	while (1) {
 		time_t now;
 
+		errno = 123456789;
 		func_mux(10);
+		errno = 987654321;
 
 		now = time(NULL);
 		if (now > last_print) {

examples/c/app_lib.c

@@ -1,5 +1,8 @@
 __thread int tls_shared;
+__thread int tls_shared2;
 static __thread int tls_local_shared;
 
 int get_tls_local_shared(void) { return tls_local_shared; }
+int get_tls_shared(void) { return tls_shared; }
+int get_tls_shared2(void) { return tls_shared2; }
 void bump_tls_local_shared(void) { tls_local_shared += 16; }