Implement get trap for proxies.

test/cctest/test-debug.cc

Index: test/cctest/test-debug.cc
diff --git a/test/cctest/test-debug.cc b/test/cctest/test-debug.cc
index 852c6d4db91189cdd53a61642cf911ee3a223255..d8c1876a9fd4cb5765e69d2a10d0730a29e14b69 100644
--- a/test/cctest/test-debug.cc
+++ b/test/cctest/test-debug.cc
@@ -4264,9 +4264,9 @@ TEST(InterceptorPropertyMirror) {
                  "named_values[%d] instanceof debug.PropertyMirror", i);
     CHECK(CompileRun(buffer.start())->BooleanValue());
 
-    // 4 is PropertyType.Interceptor
+    // 5 is PropertyType.Interceptor
     OS::SNPrintF(buffer, "named_values[%d].propertyType()", i);
-    CHECK_EQ(4, CompileRun(buffer.start())->Int32Value());
+    CHECK_EQ(5, CompileRun(buffer.start())->Int32Value());
 
     OS::SNPrintF(buffer, "named_values[%d].isNative()", i);
     CHECK(CompileRun(buffer.start())->BooleanValue());