### Godot version

4.0.beta16

### System information

Windows 10 Pro x64, GLES3, RTX 3080 Ti (528.02)

### Issue description

In Compatibility/GLES3 back-end, shaders which use a uniform to get the normal roughness buffer cannot compile. For example, the shader:
```glsl
shader_type spatial;

uniform sampler2D normal_roughness_texture : hint_normal_roughness_texture;

void fragment() {
    vec4 sample = texture(normal_roughness_texture, UV);
}
```
results in an error in the output:
```
  drivers/gles3/shader_gles3.cpp:242 - SceneShaderGLES3: Fragment shader compilation failed:
  0(890) : error C1503: undefined variable "normal_roughness_buffer"
  
  drivers/gles3/shader_gles3.cpp:342 - Method/function failed.
```

If I switch over to the Mobile or Forward+ backends, there is no shader compilation error.

### Steps to reproduce

Open the attached reproduction in the 4.0.beta16 editor.

When the scene is opened, the error is produced automatically:
1. Open `scene.tscn`
2. Open Output to review error

When the scene is saved with any changes made to the shader, the same error is also produced:
1. Open `scene.tscn`
2. Open `example.gdshader` in the shader editor.
3. Make a compile-able change to the shader.
4. Save the scene
5. Open Output to review the error

### Minimal reproduction project

[NormalRoughnessTexture_GLES3_Error.zip](https://github.com/godotengine/godot/files/10534253/NormalRoughnessTexture_GLES3_Error.zip)

if (tk.type == TK_CURSOR) {
				*r_complete_arg = p_func->arguments.size() - 1;
			} else {
				_set_tkpos(pos);
			}
		}
		Node *arg = _parse_and_reduce_expression(p_block, p_function_info);
		if (!arg) {
			return false;
		}
		p_func->arguments.push_back(arg);
		tk = _get_token();
		if (tk.type == TK_PARENTHESIS_CLOSE) {
			return true;
		} else if (tk.type != TK_COMMA) {
			
			_set_error(RTR("Expected ',' or ')' after argument."));
			return false;
		}
	}
	return true;
}
bool ShaderLanguage::is_token_operator(TokenType p_type) {
	return (p_type == TK_OP_EQUAL ||
			p_type == TK_OP_NOT_EQUAL ||
			p_type == TK_OP_LESS ||
			p_type == TK_OP_LESS_EQUAL ||
			p_type == TK_OP_GREATER ||
			p_type == TK_OP_GREATER_EQUAL ||
			p_type == TK_OP_AND ||