use Clang++ on Windows from HIP SDK

src/include/migraphx/compile_src.hpp

@@ -25,6 +25,9 @@
 #define MIGRAPHX_GUARD_MIGRAPHX_COMPILE_SRC_HPP
 
 #include <migraphx/config.hpp>
+#ifdef _WIN32
+#include <migraphx/env.hpp>
+#endif
 #include <migraphx/filesystem.hpp>
 #include <functional>
 #include <string>
@@ -51,9 +54,17 @@ struct src_file
     }
 };
 
+#ifdef _WIN32
+MIGRAPHX_DECLARE_ENV_VAR(HIP_PATH)
+#endif
+
 struct MIGRAPHX_EXPORT src_compiler
 {
+#ifdef _WIN32
+    std::string compiler = (fs::path{string_value_of(HIP_PATH{})} / "bin" / "clang++.exe").string();
+#else
     std::string compiler                      = "c++";
+#endif
     std::string flags                         = "";
     std::string output                        = "";
     std::string launcher                      = "";