SWDEV-301289 - Treewide macro rename

ATI_OS_WIN -> _WIN32
ATI_OS_LINUX -> __linux__

We should not rely on non-standard macros for platform detections.

Change-Id: If1d06e2e1187268df62a59609ea5496ab7eb709d


[ROCm/clr commit: c4aa6febe5]

projects/clr/opencl/tests/ocltst/module/runtime/OCLReadWriteImage.cpp

@@ -25,7 +25,7 @@
 #include <string.h>
 
 #include <sstream>
-#ifdef ATI_OS_LINUX
+#ifdef __linux__
 #include <sys/sysinfo.h>
 #include <unistd.h>
 #endif