Improve DYNAMIC_IMPORT

Don't call get_proc_address every time if if failed.
Also rename Utilities/dynamic_library.h to util/dyn_lib.hpp

rpcs3/util/dyn_lib.cpp

@@ -0,0 +1,69 @@
+#include "stdafx.h"
+#include "dyn_lib.hpp"
+
+#ifdef _WIN32
+	#include <Windows.h>
+#else
+	#include <dlfcn.h>
+#endif
+
+namespace utils
+{
+	dynamic_library::dynamic_library(const std::string& path)
+	{
+		load(path);
+	}
+
+	dynamic_library::~dynamic_library()
+	{
+		close();
+	}
+
+	bool dynamic_library::load(const std::string& path)
+	{
+#ifdef _WIN32
+		m_handle = LoadLibraryA(path.c_str());
+#else
+		m_handle = dlopen(path.c_str(), RTLD_LAZY);
+#endif
+		return loaded();
+	}
+
+	void dynamic_library::close()
+	{
+#ifdef _WIN32
+		FreeLibrary(reinterpret_cast<HMODULE>(m_handle));
+#else
+		dlclose(m_handle);
+#endif
+		m_handle = nullptr;
+	}
+
+	void* dynamic_library::get_impl(const std::string& name) const
+	{
+#ifdef _WIN32
+		return reinterpret_cast<void*>(GetProcAddress(reinterpret_cast<HMODULE>(m_handle), name.c_str()));
+#else
+		return dlsym(m_handle, name.c_str());
+#endif
+	}
+
+	bool dynamic_library::loaded() const
+	{
+		return m_handle != nullptr;
+	}
+
+	dynamic_library::operator bool() const
+	{
+		return loaded();
+	}
+
+	void* get_proc_address(const char* lib, const char* name)
+	{
+#ifdef _WIN32
+		return reinterpret_cast<void*>(GetProcAddress(GetModuleHandleA(lib), name));
+#else
+		return dlsym(dlopen(lib, RTLD_NOLOAD), name);
+#endif
+	}
+}