Fix size_t issues across JPEG versions and platforms (#4439)

* Windows use size_t

* Temporarily pin jpeg <=9b

* Temporarily pin jpeg ==9c

* Remove pinning.

torchvision/csrc/io/image/cpu/encode_jpeg.cpp

@@ -15,11 +15,7 @@ torch::Tensor encode_jpeg(const torch::Tensor& data, int64_t quality) {
 #else
 // For libjpeg version <= 9b, the out_size parameter in jpeg_mem_dest() is
 // defined as unsigned long, whereas in later version, it is defined as size_t.
-// For windows backward compatibility, we define JpegSizeType as different types
-// according to the libjpeg version used, in order to prevent compilation
-// errors.
-#if defined(_WIN32) || !defined(JPEG_LIB_VERSION_MAJOR) || \
-    JPEG_LIB_VERSION_MAJOR < 9 ||                          \
+#if !defined(JPEG_LIB_VERSION_MAJOR) || JPEG_LIB_VERSION_MAJOR < 9 || \
     (JPEG_LIB_VERSION_MAJOR == 9 && JPEG_LIB_VERSION_MINOR <= 2)
 using JpegSizeType = unsigned long;
 #else