missing length check in value declaration

[ltzmaxwell]

This does not compile as expected, aside from the error message, which suggests that a sanity check should be performed instead of a simple type assertion.

package main

func main() {
	var a, b = 1
}

// Error:
// interface conversion: gnolang.Expr is *gnolang.ConstExpr, not *gnolang.CallExpr

This situation is similar in that it doesn't compile as expected, but the error message indicates that it should be checked beforehand, possibly within predefineFileSet, and then halted.

package main

func main() {
	var a, b, c = 1, a + 1
	println(a)
	println(b)
	println(c)
}

// Error:
// main/files/value_decl1.gno:3: constant definition loop with a: