move some files to more reasonable locations

src/legacy/polyfills/focusPreventScroll.js

@@ -0,0 +1,42 @@
+// Polyfill to add support for preventScroll by focus function
+
+if (HTMLElement.prototype.nativeFocus === undefined) {
+    (function () {
+        var supportsPreventScrollOption = false;
+        try {
+            var focusElem = document.createElement("div");
+
+            focusElem.addEventListener("focus", function(event) {
+                event.preventDefault();
+                event.stopPropagation();
+            }, true);
+
+            var opts = Object.defineProperty({}, "preventScroll", {
+                // eslint-disable-next-line getter-return
+                get: function () {
+                    supportsPreventScrollOption = true;
+                }
+            });
+
+            focusElem.focus(opts);
+        } catch (e) {
+            console.error("error checking preventScroll support");
+        }
+
+        if (!supportsPreventScrollOption) {
+            HTMLElement.prototype.nativeFocus = HTMLElement.prototype.focus;
+
+            HTMLElement.prototype.focus = function(options) {
+                var scrollX = window.scrollX;
+                var scrollY = window.scrollY;
+
+                this.nativeFocus();
+
+                // Restore window scroll if preventScroll
+                if (options && options.preventScroll) {
+                    window.scroll(scrollX, scrollY);
+                }
+            };
+        }
+    })();
+}

src/legacy/polyfills/objectassign.js

@@ -0,0 +1,24 @@
+if (typeof Object.assign != 'function') {
+    (function () {
+        Object.assign = function (target) {
+            'use strict';
+            if (target === undefined || target === null) {
+                throw new TypeError('Cannot convert undefined or null to object');
+            }
+
+            var output = Object(target);
+            for (var index = 1; index < arguments.length; index++) {
+                var source = arguments[index];
+                if (source !== undefined && source !== null) {
+                    for (var nextKey in source) {
+                        // eslint-disable-next-line no-prototype-builtins
+                        if (source.hasOwnProperty(nextKey)) {
+                            output[nextKey] = source[nextKey];
+                        }
+                    }
+                }
+            }
+            return output;
+        };
+    })();
+}