[gcc(refs/users/ibuclaw/heads/darwin)] D, Darwin : Make the Darwin code path more obvious (NFC).

[Iain Buclaw <ibuclaw@gcc.gnu.org>]

https://gcc.gnu.org/g:8ab997f35fca804ac32e4767b82b5f61f487a951

commit 8ab997f35fca804ac32e4767b82b5f61f487a951
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Thu Dec 10 14:09:09 2020 +0000

    D, Darwin : Make the Darwin code path more obvious (NFC).
    
    Darwin passes version (Darwin) _and_ version(Posix) thus the
    AsmExternal and AsmX86*_Posix cases were already in effect.
    This just makes it more obvious (and also eases switching to
    ucontext for testing).

Diff:
---
 libphobos/libdruntime/core/thread/fiber.d | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/libphobos/libdruntime/core/thread/fiber.d b/libphobos/libdruntime/core/thread/fiber.d
index f4c04ce7358..64e90182596 100644
--- a/libphobos/libdruntime/core/thread/fiber.d
+++ b/libphobos/libdruntime/core/thread/fiber.d
@@ -76,6 +76,11 @@ private
             // fiber_switchContext does not support shadow stack from
             // Intel CET.  So use ucontext implementation.
         }
+        else version (OSX)
+        {
+            version = AsmExternal;
+            version = AsmX86_Posix;
+        }
         else
         {
             version = AsmExternal;
@@ -101,6 +106,11 @@ private
         {
             // let X32 be handled by ucontext swapcontext
         }
+        else version (OSX)
+        {
+            version = AsmExternal;
+            version = AsmX86_Posix;
+        }
         else
         {
             version = AsmExternal;