fix '--enable-visibility' build

Author: zdenop

src/arch/simddetect.h

@@ -52,7 +52,7 @@ class SIMDDetect {
   }
 
   // Update settings after config variable was set.
-  static void Update();
+  static TESS_API void Update();
 
  private:
   // Constructor, must set all static member variables.

src/dict/dict.h

@@ -301,7 +301,7 @@ class Dict {
 
   /// Initialize Dict class - load dawgs from [lang].traineddata and
   /// user-specified wordlist and parttern list.
-  static DawgCache *GlobalDawgCache();
+  static TESS_API DawgCache *GlobalDawgCache();
   // Sets up ready for a Load or LoadLSTM.
   void SetupForLoad(DawgCache *dawg_cache);
   // Loads the dawgs needed by Tesseract. Call FinishLoad() after.