func f8(r rune) {
	const x = 10
	switch r {
	case 33, 33:  
	case 34, '"':  
	case 35, rune('#'):  
	case 36, rune(36):  
	case 37, '$'+1:  
	case 'b':
	case 'a', 'b', 'c', 'd':  
	case x, x:  
	}
}
Ensure duplicates with simple literals are printed as they were
written, not just their values. Particularly useful for runes.
package main
func f0(x int) {
	switch x {
	case 0:
	case 0:  
	}
	switch x {
	case 0:
	case int(0):  
	}
}
func f1(x float32) {
	switch x {
	case 5:
	case 5:  
	case 5.0:  
	}
}
func f2(s string) {
	switch s {
	case "":
	case "":  
	case "abc":
	case "abc":  
	}
}
func f3(e interface{}) {
	switch e {
	case 0:
	case 0:  
	case int64(0):
	case float32(10):
	case float32(10):  
	case float64(10):
	case float64(10):  
	}
}
func f5(a [1]int) {
	switch a {
	case [1]int{0}:
	case [1]int{0}:  
	}
}
func f6() int {
	switch {
	case 0 == 0:
		return 0
	case 1 == 1:  
		return 1
	}
	return 2
}
func f7(a int) {
	switch a {
	case 0:
	case 0, 1:  
	case 1, 2, 3, 4:  
	}
}