Define feature test macros in common.h

This enables necessary functions once for all.

As a consequence, define common.h before any other header.

app/tests/test_buffer_util.c

@@ -1,3 +1,5 @@
+#include "common.h"
+
 #include <assert.h>
 
 #include "util/buffer_util.h"

app/tests/test_cbuf.c

@@ -1,3 +1,5 @@
+#include "common.h"
+
 #include <assert.h>
 #include <string.h>
 

app/tests/test_cli.c

@@ -1,7 +1,8 @@
+#include "common.h"
+
 #include <assert.h>
 #include <string.h>
 
-#include "common.h"
 #include "cli.h"
 #include "scrcpy.h"
 

app/tests/test_control_msg_serialize.c

@@ -1,3 +1,5 @@
+#include "common.h"
+
 #include <assert.h>
 #include <string.h>
 

app/tests/test_device_msg_deserialize.c

@@ -1,3 +1,5 @@
+#include "common.h"
+
 #include <assert.h>
 #include <string.h>
 

app/tests/test_queue.c

@@ -1,3 +1,5 @@
+#include "common.h"
+
 #include <assert.h>
 
 #include "util/queue.h"

app/tests/test_strutil.c

@@ -1,3 +1,5 @@
+#include "common.h"
+
 #include <assert.h>
 #include <limits.h>
 #include <stdio.h>