patch libdispatch BlocksRuntime header

libBlocksRuntime does not export the symbols correctly when building on
Windows.

Author: hmelder

patches/libdispatch-export-blocksrt.patch

@@ -0,0 +1,53 @@
+diff --git a/src/BlocksRuntime/Block_private.h b/src/BlocksRuntime/Block_private.h
+index b2e1512..df6fa19 100644
+--- a/src/BlocksRuntime/Block_private.h
++++ b/src/BlocksRuntime/Block_private.h
+@@ -197,9 +197,17 @@ BLOCK_EXPORT bool _Block_tryRetain(const void *aBlock);
+ // Callable only from the ARR weak subsystem while in exclusion zone
+ BLOCK_EXPORT bool _Block_isDeallocating(const void *aBlock);
+ 
+-
+ // the raw data space for runtime classes for blocks
+ // class+meta used for stack, malloc, and collectable based blocks
++#if defined(_WIN32)
++extern void * _NSConcreteMallocBlock[32];
++extern void * _NSConcreteAutoBlock[32];
++extern void * _NSConcreteFinalizingBlock[32];
++extern void * _NSConcreteWeakBlockVariable[32];
++// declared in Block.h
++// extern void * _NSConcreteGlobalBlock[32];
++// extern void * _NSConcreteStackBlock[32];
++#else
+ BLOCK_EXPORT void * _NSConcreteMallocBlock[32];
+ BLOCK_EXPORT void * _NSConcreteAutoBlock[32];
+ BLOCK_EXPORT void * _NSConcreteFinalizingBlock[32];
+@@ -207,6 +215,7 @@ BLOCK_EXPORT void * _NSConcreteWeakBlockVariable[32];
+ // declared in Block.h
+ // BLOCK_EXPORT void * _NSConcreteGlobalBlock[32];
+ // BLOCK_EXPORT void * _NSConcreteStackBlock[32];
++#endif
+ 
+ 
+ // the intercept routines that must be used under GC
+diff --git a/src/BlocksRuntime/data.c b/src/BlocksRuntime/data.c
+index fe4745b..f96ea25 100644
+--- a/src/BlocksRuntime/data.c
++++ b/src/BlocksRuntime/data.c
+@@ -19,12 +19,15 @@ We keep these in a separate file so that we can include the runtime code in test
+ #if defined(_WIN32)
+ void * _NSConcreteStackBlock[32] = { 0 };
+ void * _NSConcreteGlobalBlock[32] = { 0 };
++void * _NSConcreteMallocBlock[32] = { 0 };
++void * _NSConcreteAutoBlock[32] = { 0 };
++void * _NSConcreteFinalizingBlock[32] = { 0 };
++void * _NSConcreteWeakBlockVariable[32] = { 0 };
+ #else
+ BLOCK_ABI void * _NSConcreteStackBlock[32] = { 0 };
+ BLOCK_ABI void * _NSConcreteGlobalBlock[32] = { 0 };
+-#endif
+-
+ BLOCK_ABI void * _NSConcreteMallocBlock[32] = { 0 };
+ BLOCK_ABI void * _NSConcreteAutoBlock[32] = { 0 };
+ BLOCK_ABI void * _NSConcreteFinalizingBlock[32] = { 0 };
+ BLOCK_ABI void * _NSConcreteWeakBlockVariable[32] = { 0 };
++#endif