Make Cmake work with debug build

include/private/SkSpinlock.h

Index: include/private/SkSpinlock.h
diff --git a/include/private/SkSpinlock.h b/include/private/SkSpinlock.h
index a049f1f726a8db827e6610c026ce18aa43c15922..27442068717b319f6bd56cda1fc327150b71f057 100644
--- a/include/private/SkSpinlock.h
+++ b/include/private/SkSpinlock.h
@@ -8,6 +8,7 @@
 #ifndef SkSpinlock_DEFINED
 #define SkSpinlock_DEFINED
 
+#include "SkTypes.h"
 #include <atomic>
 
 class SkSpinlock {
@@ -26,7 +27,7 @@ public:
     }
 
 private:
-    void contendedAcquire();
+    SK_API void contendedAcquire();
 
     std::atomic<bool> fLocked{false};
 };