Mark Number and String as strict functions

As required by #sec-built-in-function-objects.
They were strict functions before (see
e2f1c269), but that got lost when they
were ported to ASM builtins.
This makes optimized and non-optimized code agree on the same behavior
in regress-105.js.

BUG=v8:105,v8:5778,v8:6325

Review-Url: https://codereview.chromium.org/2848313004
Cr-Commit-Position: refs/heads/master@{#45012}

src/bootstrapper.cc

@@ -1595,6 +1595,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     number_fun->shared()->SetConstructStub(
         *isolate->builtins()->NumberConstructor_ConstructStub());
     number_fun->shared()->set_length(1);
+    // https://tc39.github.io/ecma262/#sec-built-in-function-objects says
+    // that "Built-in functions that are ECMAScript function objects must
+    // be strict functions".
+    number_fun->shared()->set_language_mode(STRICT);
     InstallWithIntrinsicDefaultProto(isolate, number_fun,
                                      Context::NUMBER_FUNCTION_INDEX);
 
@@ -1740,6 +1744,10 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
         *isolate->builtins()->StringConstructor_ConstructStub());
     string_fun->shared()->DontAdaptArguments();
     string_fun->shared()->set_length(1);
+    // https://tc39.github.io/ecma262/#sec-built-in-function-objects says
+    // that "Built-in functions that are ECMAScript function objects must
+    // be strict functions".
+    string_fun->shared()->set_language_mode(STRICT);
     InstallWithIntrinsicDefaultProto(isolate, string_fun,
                                      Context::STRING_FUNCTION_INDEX);
 

test/mjsunit/mjsunit.status

@@ -186,10 +186,6 @@
   #                  which makes the test useless.
   'big-object-literal': [PASS, ['mode == debug', SKIP]],
 
-  # BUG(v8:5778): These fail with --future, which we are about to turn on.
-  # Investigate.
-  'regress/regress-105': [SKIP],
-
   # BUG(v8:6101): This fails because of a hole deopt, need to investigate.
   'getters-on-elements': [SKIP],
 

test/mjsunit/regress/regress-105.js

@@ -26,12 +26,12 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 var custom_valueOf = function() {
-  assertEquals(Number, custom_valueOf.caller);
+  assertEquals(null, custom_valueOf.caller);
   return 2;
 }
 
 var custom_toString = function() {
-  assertEquals(String, custom_toString.caller);
+  assertEquals(null, custom_toString.caller);
   return "I used to be an adventurer like you";
 }