Using gladLoadGLLoader with SDL_GL_GetProcAddress crashes in Release mode
Hi,

I've been using glad for many months and it's absolutely fantastic. However, I've encountered an issue while attempting to use `SDL_GL_GetProcAddress` with `gladLoadGLLoader()`.

When I compile my program in the *Debug* configuration, everything works perfectly. However, when compiling my program as *Release*, I encounter a crash at the first gl call, even if `gladLoadGLLoader()` returned `true`.

Here is the value of that first gl call if it helps: `glDepthFunc: 0x8CC35900`.

Using the built-in `gladLoadGL()` works perfectly in both *Debug* and *Release* configurations.

**Configuration**:
- glad 0.1.35 (webservice)
- C++, OpenGL 2.1 Core Profile, no extensions
- SDL 2.0.9
- Windows 11 Visual Studio 2022

**Usage**:
```
gladLoadGLLoader((GLADloadproc)SDL_GL_GetProcAddress);
```

Thanks for the help!