core: rework code locality

- to reduce binaries size of FFmpeg Windows wrapper
- MinGW linker doesn't support -ffunction-sections (used for FFmpeg Windows wrapper)
- move code to improve locality with its used dependencies
- move UMat::dot() to matmul.dispatch.cpp (Mat::dot() is already there)
- move UMat::inv() to lapack.cpp
- move UMat::mul() to arithm.cpp
- move UMat:eye() to matrix_operations.cpp (near setIdentity() implementation)
- move normalize(): convert_scale.cpp => norm.cpp
- move convertAndUnrollScalar(): arithm.cpp => copy.cpp
- move scalarToRawData(): array.cpp => copy.cpp
- move transpose(): matrix_operations.cpp => matrix_transform.cpp
- move flip(), rotate(): copy.cpp => matrix_transform.cpp (rotate90 uses flip and transpose)
- add 'OPENCV_CORE_EXCLUDE_C_API' CMake variable to exclude compilation of C-API functions from the core module
- matrix_wrap.cpp: add compile-time checks for CUDA/OpenGL calls
- the steps above allow to reduce FFmpeg wrapper size for ~1.5Mb (initial size of OpenCV part is about 3Mb)

modules/core/src/convert_c.cpp

@@ -5,6 +5,7 @@
 
 #include "precomp.hpp"
 
+#ifndef OPENCV_EXCLUDE_C_API
 
 CV_IMPL void
 cvSplit( const void* srcarr, void* dstarr0, void* dstarr1, void* dstarr2, void* dstarr3 )
@@ -132,3 +133,5 @@ CV_IMPL void cvNormalize( const CvArr* srcarr, CvArr* dstarr,
     CV_Assert( dst.size() == src.size() && src.channels() == dst.channels() );
     cv::normalize( src, dst, a, b, norm_type, dst.type(), mask );
 }
+
+#endif  // OPENCV_EXCLUDE_C_API