fix corner case in parsing directives (#3615)

test/compress/functions.js

@@ -2004,57 +2004,6 @@ deduplicate_parenthesis: {
     expect_exact: "({}).a=b;({}.a=b)();(function(){}).a=b;(function(){}.a=b)();"
 }
 
-drop_lone_use_strict: {
-    options = {
-        directives: true,
-        side_effects: true,
-    }
-    input: {
-        function f1() {
-            "use strict";
-        }
-        function f2() {
-            "use strict";
-            function f3() {
-                "use strict";
-            }
-        }
-        (function f4() {
-            "use strict";
-        })();
-    }
-    expect: {
-        function f1() {
-        }
-        function f2() {
-            "use strict";
-            function f3() {
-            }
-        }
-    }
-}
-
-issue_3166: {
-    options = {
-        directives: true,
-    }
-    input: {
-        "foo";
-        "use strict";
-        function f() {
-            "use strict";
-            "bar";
-            "use asm";
-        }
-    }
-    expect: {
-        "use strict";
-        function f() {
-            "use asm";
-        }
-    }
-}
-
 issue_3016_1: {
     options = {
         inline: true,