Fix missing context APIs in version strings

src/cocoa_init.m

@@ -585,7 +585,7 @@ void _glfwPlatformTerminate(void)
 
 const char* _glfwPlatformGetVersionString(void)
 {
-    return _GLFW_VERSION_NUMBER " Cocoa NSGL"
+    return _GLFW_VERSION_NUMBER " Cocoa NSGL EGL OSMesa"
 #if defined(_GLFW_BUILD_DLL)
         " dynamic"
 #endif

src/win32_init.c

@@ -612,7 +612,7 @@ void _glfwPlatformTerminate(void)
 
 const char* _glfwPlatformGetVersionString(void)
 {
-    return _GLFW_VERSION_NUMBER " Win32 WGL EGL"
+    return _GLFW_VERSION_NUMBER " Win32 WGL EGL OSMesa"
 #if defined(__MINGW32__)
         " MinGW"
 #elif defined(_MSC_VER)

src/wl_init.c

@@ -1306,7 +1306,7 @@ void _glfwPlatformTerminate(void)
 
 const char* _glfwPlatformGetVersionString(void)
 {
-    return _GLFW_VERSION_NUMBER " Wayland EGL"
+    return _GLFW_VERSION_NUMBER " Wayland EGL OSMesa"
 #if defined(_POSIX_TIMERS) && defined(_POSIX_MONOTONIC_CLOCK)
         " clock_gettime"
 #else

src/x11_init.c

@@ -1083,7 +1083,7 @@ void _glfwPlatformTerminate(void)
 
 const char* _glfwPlatformGetVersionString(void)
 {
-    return _GLFW_VERSION_NUMBER " X11 GLX EGL"
+    return _GLFW_VERSION_NUMBER " X11 GLX EGL OSMesa"
 #if defined(_POSIX_TIMERS) && defined(_POSIX_MONOTONIC_CLOCK)
         " clock_gettime"
 #else