Fixed compilation error on Windows

platforms/cpu/tests/CpuTests.h

@@ -29,6 +29,9 @@
  * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
  * -------------------------------------------------------------------------- */
 
+#ifdef WIN32
+  #define _USE_MATH_DEFINES // Needed to get M_PI
+#endif
 #include "CpuPlatform.h"
 #include <cstdlib>
 #include <iostream>

platforms/cuda/tests/CudaTests.h

@@ -29,6 +29,9 @@
  * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
  * -------------------------------------------------------------------------- */
 
+#ifdef WIN32
+  #define _USE_MATH_DEFINES // Needed to get M_PI
+#endif
 #include "CudaPlatform.h"
 #include <string>
 

platforms/opencl/tests/OpenCLTests.h

@@ -29,6 +29,9 @@
  * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
  * -------------------------------------------------------------------------- */
 
+#ifdef WIN32
+  #define _USE_MATH_DEFINES // Needed to get M_PI
+#endif
 #include "OpenCLPlatform.h"
 #include <string>
 

platforms/reference/tests/ReferenceTests.h

@@ -29,6 +29,9 @@
  * USE OR OTHER DEALINGS IN THE SOFTWARE.                                     *
  * -------------------------------------------------------------------------- */
 
+#ifdef WIN32
+  #define _USE_MATH_DEFINES // Needed to get M_PI
+#endif
 #include "ReferencePlatform.h"
 
 OpenMM::ReferencePlatform platform;