Linking glad to project with glfw
I'm trying to make a cross-platform compilation to build a project on Linux, which will be used on windows.

But I'm stuck with these linking errors:
```
    /usr/bin/ld: bin/Release-linux-x86_64/glad/libglad.a(glad.o):glad.c:(.text+0x2aa6): undefined reference to `__imp_GetProcAddress'
    /usr/bin/ld: bin/Release-linux-x86_64/glad/libglad.a(glad.o):glad.c:(.text+0x4abf): undefined reference to `__imp_LoadLibraryW'
    /usr/bin/ld: bin/Release-linux-x86_64/glad/libglad.a(glad.o):glad.c:(.text+0x4aec): undefined reference to `__imp_GetProcAddress'
    /usr/bin/ld: bin/Release-linux-x86_64/glad/libglad.a(glad.o):glad.c:(.text+0x4b19): undefined reference to `__imp_FreeLibrary'
```
I'm using these flags to link libraries:
```
    LINKCMD = $(CXX) -o "$@" $(OBJECTS) $(RESOURCES) $(ALL_LDFLAGS) $(LIBS)
    LIBS += bin/Release-linux-x86_64/glad/libglad.a bin/Release-linux-x86_64/GLFW/libGLFW.a
    LDDEPS += bin/Release-linux-x86_64/GLFW/libGLFW.a bin/Release-linux-x86_64/glad/libglad.a
    ALL_LDFLAGS += $(LDFLAGS) -L/usr/lib64 -m64 -s -lglfw -pthread -lGLU -lGL -lrt -lXrandr -lXxf86vm -lXi -lXinerama -lX11 -ldl
```
To build and compile libraries I'm using makefile from these premake files.

premake for glad:
```
    project "Glad"
    kind "StaticLib"
    language "C"
    staticruntime "on"
    
    targetdir ("bin/" .. outputdir .. "/%{prj.name}")
    objdir ("bin-int/" .. outputdir .. "/%{prj.name}")

    files
    {
        "include/glad/glad.h",
        "include/KHR/khrplatform.h",
        "src/glad.c"
    }

    includedirs
    {
        "include"
    }
	
    filter "configurations:Debug"
        runtime "Debug"
        symbols "on"

    filter "configurations:Release"
        runtime "Release"
        optimize "on"
```
premake for glfw:
```

    project "GLFW"
	kind "StaticLib"
	language "C"

	targetdir ("bin/" .. outputdir .. "/%{prj.name}")
	objdir ("bin-int/" .. outputdir .. "/%{prj.name}")

	files
	{
		"include/GLFW/glfw3.h",
		"include/GLFW/glfw3native.h",
		"src/glfw_config.h",
		"src/context.c",
		"src/init.c",
		"src/input.c",
		"src/monitor.c",
		"src/vulkan.c",
		"src/window.c"
	}
	filter "system:linux"
		pic "On"

		systemversion "latest"
		staticruntime "On"

		files
		{
			"src/x11_init.c",
			"src/x11_monitor.c",
			"src/x11_window.c",
			"src/xkb_unicode.c",
			"src/posix_time.c",
			"src/posix_thread.c",
			"src/glx_context.c",
			"src/egl_context.c",
			"src/osmesa_context.c",
			"src/linux_joystick.c"
		}

		defines
		{
			"_GLFW_X11"
		}

	filter "system:windows"
		systemversion "latest"
		staticruntime "On"

		files
		{
			"src/win32_init.c",
			"src/win32_joystick.c",
			"src/win32_monitor.c",
			"src/win32_time.c",
			"src/win32_thread.c",
			"src/win32_window.c",
			"src/wgl_context.c",
			"src/egl_context.c",
			"src/osmesa_context.c"
		}

		defines 
		{ 
			"_GLFW_WIN32",
			"_CRT_SECURE_NO_WARNINGS"
		}

	filter "configurations:Debug"
		runtime "Debug"
		symbols "on"

	filter "configurations:Release"
		runtime "Release"
		optimize "on"
```

- Platform: Ubuntu
- C++ Compilator: x86_64-w64-mingw32-g++
- C Compilator: x86_64-w64-mingw32-gcc