Commit b1731b6e for tesseract

commit b1731b6e7357e61f01654ea386c6492f87077b59
Author: Egor Pugin <egor.pugin@gmail.com>
Date:   Wed Apr 7 00:59:36 2021 +0300

    Add missing TESS_API.

diff --git a/src/ccstruct/quspline.h b/src/ccstruct/quspline.h
index 7ccab2cc..ea27ede5 100644
--- a/src/ccstruct/quspline.h
+++ b/src/ccstruct/quspline.h
@@ -33,7 +33,7 @@ class QUAD_COEFFS;
 class ROW;
 class TBOX;

-class QSPLINE {
+class TESS_API QSPLINE {
   friend void make_first_baseline(TBOX *, int, int *, int *, QSPLINE *, QSPLINE *, float);
   friend void make_holed_baseline(TBOX *, int, QSPLINE *, QSPLINE *, float);
   friend void tweak_row_baseline(ROW *, double, double);