Basic render target/framebuffer setup.

src/xenia/gpu/gl4/gl_context.cc

@@ -106,6 +106,10 @@ bool GLContext::Initialize(HWND hwnd) {
     return false;
   }
 
+  while (glGetError()) {
+    // Clearing errors.
+  }
+
   return true;
 }
 
@@ -145,6 +149,10 @@ std::unique_ptr<GLContext> GLContext::CreateShared() {
   new_context->ClearCurrent();
   MakeCurrent();
 
+  while (glGetError()) {
+    // Clearing errors.
+  }
+
   return new_context;
 }