macos: satisfy all need for clock_nanosleep()

src/poc/blitters.c

@@ -2,7 +2,7 @@
 #include <unistd.h>
 #include <locale.h>
 #include <notcurses/notcurses.h>
-#include "compat/compat.h"
+#include "compat/compat.c"
 
 int main(int argc, char** argv){
   if(setlocale(LC_ALL, "") == NULL){

src/poc/rotate.c

@@ -5,7 +5,7 @@
 #include <assert.h>
 #include <unistd.h>
 #include <notcurses/notcurses.h>
-#include "compat/compat.h"
+#include "compat/compat.c"
 
 int main(int argc, char** argv){
   struct timespec ts = {

src/poc/textplay.c

@@ -1,6 +1,6 @@
 #include <stdlib.h>
 #include <notcurses/notcurses.h>
-#include "compat/compat.h"
+#include "compat/compat.c"
 
 #define GIG 1000000000ull
 static const uint32_t LOWCOLOR = 0x004080;