Fix handling of this in direct calls to function proxies.

src/messages.js

Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index a9993af22950470ab0045500ee74dd7855f8ccda..be236a4a34a95bd4ccd31bfcabfb437d87df2b3f 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -185,14 +185,14 @@ function FormatMessage(message) {
       "define_disallowed",            ["Cannot define property:", "%0", ", object is not extensible."],
       "non_extensible_proto",         ["%0", " is not extensible"],
       "handler_non_object",           ["Proxy.", "%0", " called with non-object as handler"],
-      "trap_function_expected",       ["Proxy.", "%0", " called with non-function for ", "%1", " trap"],
+      "trap_function_expected",       ["Proxy.", "%0", " called with non-function for '", "%1", "' trap"],
       "handler_trap_missing",         ["Proxy handler ", "%0", " has no '", "%1", "' trap"],
       "handler_trap_must_be_callable", ["Proxy handler ", "%0", " has non-callable '", "%1", "' trap"],
-      "handler_returned_false",       ["Proxy handler ", "%0", " returned false for '", "%1", "' trap"],
-      "handler_returned_undefined",   ["Proxy handler ", "%0", " returned undefined for '", "%1", "' trap"],
-      "proxy_prop_not_configurable",  ["Trap ", "%1", " of proxy handler ", "%0", " returned non-configurable descriptor for property ", "%2"],
-      "proxy_non_object_prop_names",  ["Trap ", "%1", " returned non-object ", "%0"],
-      "proxy_repeated_prop_name",     ["Trap ", "%1", " returned repeated property name ", "%2"],
+      "handler_returned_false",       ["Proxy handler ", "%0", " returned false from '", "%1", "' trap"],
+      "handler_returned_undefined",   ["Proxy handler ", "%0", " returned undefined from '", "%1", "' trap"],
+      "proxy_prop_not_configurable",  ["Proxy handler ", "%0", " returned non-configurable descriptor for property '", "%2", "' from '", "%1", "' trap"],
+      "proxy_non_object_prop_names",  ["Trap '", "%1", "' returned non-object ", "%0"],
+      "proxy_repeated_prop_name",     ["Trap '", "%1", "' returned repeated property name '", "%2", "'"],
       "invalid_weakmap_key",          ["Invalid value used as weak map key"],
       // RangeError
       "invalid_array_length",         ["Invalid array length"],