Merge pull request #747 from Platin21/master

Fixes for MacOS 11 / Big Sur

core/os/os_darwin.odin

@@ -1,8 +1,8 @@
 package os
 
 foreign import dl   "system:dl"
-foreign import libc "system:c"
-foreign import pthread "system:pthread"
+foreign import libc "System.framework"
+foreign import pthread "System.framework"
 
 import "core:runtime"
 import "core:strings"

core/sys/darwin/mach_darwin.odin

@@ -1,6 +1,6 @@
 package darwin;
 
-foreign import "system:pthread"
+foreign import pthread "System.framework"
 
 import "core:c"
 

core/time/time_unix.odin

@@ -3,7 +3,12 @@ package time
 
 IS_SUPPORTED :: true; // NOTE: Times on Darwin are UTC.
 
-foreign import libc "system:c"
+when ODIN_OS == "darwin" {
+  foreign import libc "System.framework"
+} else  {
+  foreign import libc "system:c"
+}
+
 
 @(default_calling_convention="c")
 foreign libc {