[proxies] Remove "fix" functionality, add (still unused) target property.

test/mjsunit/harmony/proxies-hash.js

Index: test/mjsunit/harmony/proxies-hash.js
diff --git a/test/mjsunit/harmony/proxies-hash.js b/test/mjsunit/harmony/proxies-hash.js
index 65d2d3c5646cdbb2188a439407f30ee536795a87..b78edbf7cf10371a43898435831997a689049034 100644
--- a/test/mjsunit/harmony/proxies-hash.js
+++ b/test/mjsunit/harmony/proxies-hash.js
@@ -70,9 +70,10 @@ function TestSet2(construct, fix, create) {
   assertFalse(s.has(p3));
 }
 
-TestSet(Set, Object.seal)
-TestSet(Set, Object.freeze)
-TestSet(Set, Object.preventExtensions)
+// TODO(neis): Reenable once proxies properly support these operations.
+// TestSet(Set, Object.seal)
+// TestSet(Set, Object.freeze)
+// TestSet(Set, Object.preventExtensions)
 
 
 // Maps and weak maps.
@@ -113,10 +114,12 @@ function TestMap2(construct, fix, create) {
   assertSame(undefined, m.get(p2));
 }
 
-TestMap(Map, Object.seal)
-TestMap(Map, Object.freeze)
-TestMap(Map, Object.preventExtensions)
+// TODO(neis): Reenable once proxies properly support these operations.
+// TestMap(Map, Object.seal)
+// TestMap(Map, Object.freeze)
+// TestMap(Map, Object.preventExtensions)
 
-TestMap(WeakMap, Object.seal)
-TestMap(WeakMap, Object.freeze)
-TestMap(WeakMap, Object.preventExtensions)
+// TODO(neis): Reenable once proxies properly support these operations.
+// TestMap(WeakMap, Object.seal)
+// TestMap(WeakMap, Object.freeze)
+// TestMap(WeakMap, Object.preventExtensions)