Examples: Clang/Linux warning fixes.

examples/opengl3_example/main.cpp

@@ -1,7 +1,7 @@
 // ImGui - standalone example application for Glfw + OpenGL 3, using programmable pipeline
 
 #include <imgui.h>
-#include "imgui_impl_glfw_GL3.h"
+#include "imgui_impl_glfw_gl3.h"
 #include <stdio.h>
 #include <GL/gl3w.h>
 #include <GLFW/glfw3.h>

examples/opengl_example/imgui_impl_glfw.cpp

@@ -189,7 +189,7 @@ bool    ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks)
 
 void ImGui_ImplGlfw_Shutdown()
 {
-    if (GLuint tex_id = (GLuint)ImGui::GetIO().Fonts->TexID)
+    if (GLuint tex_id = (GLuint)(intptr_t)ImGui::GetIO().Fonts->TexID)
     {
         glDeleteTextures(1, &tex_id);
         ImGui::GetIO().Fonts->TexID = 0;