make-maybe-test file breaks IE11

[Kevin Phillips]

This should use a normal function instead of a class:

can-query-logic/src/types/make-maybe-test.js

Lines 10 to 18 in 39b3def

 class DateStringSet { 
 	constructor(value) { 
 		this.value = value; 
 	} 
 	// used to convert to a number 
 	valueOf() { 
 		return this.value == null ? this.value : new Date(this.value).getTime(); 
 	} 
 }