Revert "Revert "add more tests""

This reverts commit 4250d7f.

Author: Vercantez

test/Sema/option-set-empty.swift

@@ -7,13 +7,24 @@ struct SomeOptions: OptionSet {
     static let some = MyOptions(rawValue: 4)
     static let empty = SomeOptions(rawValue: 0) // expected-warning {{static property 'empty' produces an empty option set}} expected-note {{use [] to silence this warning}}{{35-48=([])}}
     static var otherVal = SomeOptions(rawValue: 0)
+    let option = MyOptions(float: Float.infinity)
 }
 
 struct MyOptions: OptionSet {
     let rawValue: Int
 
+    init(rawValue: Int) {
+        self.rawValue = rawValue
+    }
+
+    init(float: Float) {
+        self.rawValue = float.exponent
+    }
+    
     static let none = MyOptions(rawValue: 0) // expected-warning {{static property 'none' produces an empty option set}} expected-note {{use [] to silence this warning}}{{32-45=([])}}
     static var nothing = MyOptions(rawValue: 0)
     static let nope = MyOptions()
     static let other = SomeOptions(rawValue: 8)
+    static let piVal = MyOptions(float: Float.pi)
+    static let zero = MyOptions(float: 0.0)
 }