duplicate entries in map (and possibly slice/array) decls don't throw an error

[thehowl]

See #708

	m := map[string][]Foo{
		"hello": {Foo{"foo"}, Foo{"bar"}},
		"world": {Foo{"truc"}, Foo{"machin"}},
		"hello": {},
	}

Does not error in parsing/execution. My suspect is that this doesn't happen in array/slice declaration either (ie. []string{0: "a", 10: "b", 10: "c"}

[tbruyelle]

[]string{0: "a", 10: "b", 10: "c"}

I was wondering why you were also mentioning slices for this bug: I didn't know it was possible to create a slice like that! 😮

[thehowl]

@tbruyelle the most common use I've found in the wild is to create "cheap" maps of ie. forbidden characters and similar.

var forbidden = [256]bool{
    '$': true,
    '%': true,
    '-': true,
}

the remaining will be initialized to false as a zero value :)