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/common/BaseTestImp.cpp

@@ -45,7 +45,7 @@ BaseTestImp::BaseTestImp()
   _platformIndex = 0;
   _perfInfo = 0.0f;
 
-#ifdef ATI_OS_LINUX  //
+#ifdef __linux__  //
   _useThreads = 0;  // disable threads on linux
 #else
   _useThreads = 1;  // if available on platform