[strong] Implement strong mode semantics for the count operation.

src/ppc/full-codegen-ppc.cc

Index: src/ppc/full-codegen-ppc.cc
diff --git a/src/ppc/full-codegen-ppc.cc b/src/ppc/full-codegen-ppc.cc
index 533e097fc379ebbb1453ca3a91133b0c1bf44d1b..faacb744c47f87cb384997ae86181b3ee1d10ed8 100644
--- a/src/ppc/full-codegen-ppc.cc
+++ b/src/ppc/full-codegen-ppc.cc
@@ -5046,9 +5046,11 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
     __ b(&stub_call);
     __ bind(&slow);
   }
-  ToNumberStub convert_stub(isolate());
-  __ CallStub(&convert_stub);
-  PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
+  if (!is_strong(language_mode())) {
+    ToNumberStub convert_stub(isolate());
+    __ CallStub(&convert_stub);
+    PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
+  }
 
   // Save result for postfix expressions.
   if (expr->is_postfix()) {
@@ -5089,6 +5091,9 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   patch_site.EmitPatchInfo();
   __ bind(&done);
 
+  if (is_strong(language_mode())) {
+    PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
+  }
   // Store the value returned in r3.
   switch (assign_type) {
     case VARIABLE: