Better symbol visibility fix for unit test.
Better symbol visibility fix for unit test.

UB-Mannheim/tesseract,stweil/tesseract,tesseract-ocr/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,tesseract-ocr/tesseract,tesseract-ocr/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,stweil/tesseract,amitdo/tesseract,stweil/tesseract,stweil/tesseract,amitdo/tesseract,UB-Mannheim/tesseract,tesseract-ocr/tesseract,stweil/tesseract,tesseract-ocr/tesseract