Updated hipEnvVarDriver to work with Windows (#1614)

* Updated hipEnvVarDriver to work with Windows

* Cleaned up a bit of code

* Fixed a part where putenv was used for both win and linux

* Defines moved to test_common.h and cleaned up code

* Cleaned up some macro defines and used const char instead

* Got rid of some excess commenting

* directory paths are unconditional

* Cleaned some duplicate code, and variables are now declared and defined together

tests/src/test_common.cpp

@@ -33,7 +33,15 @@ unsigned threadsPerBlock = 256;
 int p_gpuDevice = 0;
 unsigned p_verbose = 0;
 int p_tests = -1; /*which tests to run. Interpretation is left to each test.  default:all*/
-
+#ifdef _WIN64
+const char* HIP_VISIBLE_DEVICES_STR = "HIP_VISIBLE_DEVICES=";
+const char* CUDA_VISIBLE_DEVICES_STR = "CUDA_VISIBLE_DEVICES=";
+const char* PATH_SEPERATOR_STR = "\\";
+#else
+const char* HIP_VISIBLE_DEVICES_STR = "HIP_VISIBLE_DEVICES";
+const char* CUDA_VISIBLE_DEVICES_STR = "CUDA_VISIBLE_DEVICES";
+const char* PATH_SEPERATOR_STR = "/";
+#endif
 
 namespace HipTest {