Tacos al Pastor in the Slow Cooker

½ (3 pound) boneless pork loin

or to taste

salt and ground black pepper to taste

1 (15 ounce) can crushed pineapple

divided

1 (14.5 ounce) can chicken broth

1 cup orange juice

1 small red onion

quartered

¼ cup white vinegar

2 tablespoons lime juice

1 chipotle pepper in adobo sauce

3 teaspoons minced garlic

2 teaspoons chili powder

1 ½ teaspoons salt

1 ½ teaspoons ground cumin

1 teaspoon garlic salt

1 teaspoon ground black pepper

1 teaspoon onion powder

1 teaspoon dried oregano

1 (10 ounce) package frozen corn