Remove core:os dependency for base:runtime

core/sys/unix/pthread_darwin.odin

@@ -86,7 +86,7 @@ PTHREAD_CANCEL_DISABLE      :: 1
 PTHREAD_CANCEL_DEFERRED     :: 0
 PTHREAD_CANCEL_ASYNCHRONOUS :: 1
 
-foreign import pthread "System.framework"
+foreign import pthread "system:System.framework"
 
 @(default_calling_convention="c")
 foreign pthread {

core/sys/unix/time_unix.odin

@@ -2,7 +2,7 @@
 package unix
 
 when ODIN_OS == .Darwin {
-	foreign import libc "System.framework"
+	foreign import libc "system:System.framework"
 } else  {
 	foreign import libc "system:c"
 }