Fix context initialization

core/os/os_essence.odin

@@ -71,7 +71,7 @@ stdin  := Handle(-1); // Not implemented
 stdout := Handle(0);
 stderr := Handle(0);
 
-current_thread_id :: proc() -> int {
+current_thread_id :: proc "contextless" () -> int {
 	return OSGetThreadID(Handle(0x1000));
 }
 

core/os/os_linux.odin

@@ -245,7 +245,7 @@ exit :: proc(code: int) -> ! {
 	_unix_exit(code);
 }
 
-current_thread_id :: proc() -> int {
+current_thread_id :: proc "contextless" () -> int {
 	// return int(_unix_gettid());
 	return 0;
 }

core/os/os_osx.odin

@@ -260,7 +260,7 @@ exit :: inline proc(code: int) -> ! {
 }
 
 
-current_thread_id :: proc() -> int {
+current_thread_id :: proc "contextless" () -> int {
 	// return int(_unix_gettid());
 	return 0;
 }

core/os/os_windows.odin

@@ -251,7 +251,7 @@ exit :: proc(code: int) -> ! {
 
 
 
-current_thread_id :: proc() -> int {
+current_thread_id :: proc "contextless" () -> int {
 	return int(win32.get_current_thread_id());
 }