[gcc r13-1077] libphobos: Check in missing core.sync package module

[gcc r13-1077] libphobos: Check in missing core.sync package module

[Iain Buclaw]

https://gcc.gnu.org/g:4f19e078ccb698cab1588f452bf00932fd4ef574

commit r13-1077-g4f19e078ccb698cab1588f452bf00932fd4ef574
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Tue Jun 14 00:05:35 2022 +0200

    libphobos: Check in missing core.sync package module
    
    This was meant to be part of r13-1062 in the merge with upstream
    druntime 454471d8.

Diff:
---
 libphobos/libdruntime/core/sync/package.d | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/libphobos/libdruntime/core/sync/package.d b/libphobos/libdruntime/core/sync/package.d
new file mode 100644
index 00000000000..fe389a0475d
--- /dev/null
+++ b/libphobos/libdruntime/core/sync/package.d
@@ -0,0 +1,20 @@
+/**
+ * Provides thread synchronization tools such as mutexes, semaphores and barriers.
+ *
+ * License: Distributed under the
+ *      $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost Software License 1.0).
+ *    (See accompanying file LICENSE)
+ * Authors:   Sean Kelly, Rainer Schuetze
+ * Source:    $(DRUNTIMESRC core/sync/package.d)
+ */
+
+module core.sync;
+
+public import core.sync.barrier;
+public import core.sync.condition;
+public import core.sync.config;
+public import core.sync.event;
+public import core.sync.exception;
+public import core.sync.mutex;
+public import core.sync.rwmutex;
+public import core.sync.semaphore;