Fix linux mutexes to be recursive; tombstone the old unix code

platform_linux/linux_4ed_functions.cpp

@@ -554,7 +554,10 @@ internal System_Mutex
 system_mutex_make(void){
     System_Mutex result = {};
     Linux_Object* object = linux_alloc_object(LinuxObjectKind_Mutex);
-    pthread_mutex_init(&object->mutex, NULL);
+    pthread_mutexattr_t attr;
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+    pthread_mutex_init(&object->mutex, &attr);
     *(Linux_Object**)&result = object;
     //LINUX_FN_DEBUG("%p", object);
     return result;

platform_unix/unix_4ed_functions.cpp

@@ -9,6 +9,8 @@
 
 // TOP
 
+#error IS THIS STILL REAL? (February 27th 2020)
+
 #if !defined(FD_CHECK)
 #define FD_CHECK()
 #endif

platform_unix/unix_4ed_headers.h

@@ -9,6 +9,8 @@
 
 // TOP
 
+#error IS THIS STILL REAL? (February 27th 2020)
+
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <sys/stat.h>

platform_unix/unix_library_wrapper.h

@@ -9,6 +9,8 @@
 
 // TOP
 
+#error IS THIS STILL REAL? (February 27th 2020)
+
 union Library{
     void *lib;
     FixSize(LIBRARY_TYPE_SIZE);

platform_unix/unix_threading_wrapper.h

@@ -9,6 +9,8 @@
 
 // TOP
 
+#error IS THIS STILL REAL? (February 27th 2020)
+
 #if !defined(MAC_THREADING_WRAPPER)
 #define MAC_THREADING_WRAPPER