AntTweakBar: fix dynamic loading of OpenGL framework

Closes Homebrew/homebrew#29535.

Formula/anttweakbar.rb

@@ -8,6 +8,7 @@ class Anttweakbar < Formula
 
   # See
   # http://sourceforge.net/p/anttweakbar/code/ci/5a076d13f143175a6bda3c668e29a33406479339/tree/src/LoadOGLCore.h?diff=5528b167ed12395a60949d7c643262b6668f15d5&diformat=regular
+  # https://sourceforge.net/p/anttweakbar/tickets/14/
   patch :DATA
 
   def install
@@ -50,3 +51,16 @@ index 8aaab1e..b606d2b 100644
  ANT_GL_CORE_DECL(void, glUseProgram, (GLuint program))
  ANT_GL_CORE_DECL(void, glUniform1f, (GLint location, GLfloat v0))
  ANT_GL_CORE_DECL(void, glUniform2f, (GLint location, GLfloat v0, GLfloat v1))
+diff --git a/src/LoadOGLCore.cpp b/src/LoadOGLCore.cpp
+index 2daa573..b8b9151 100644
+--- a/src/LoadOGLCore.cpp
++++ b/src/LoadOGLCore.cpp
+@@ -484,7 +484,7 @@ namespace GLCore { PFNGLGetProcAddress _glGetProcAddress = NULL; }
+         void *proc=NULL;
+         if (gl_dyld == NULL)
+         {
+-            gl_dyld = dlopen("OpenGL",RTLD_LAZY);
++            gl_dyld = dlopen("/System/Library/Frameworks/OpenGL.framework/OpenGL",RTLD_LAZY);
+         }
+         if (gl_dyld)
+         {