Only swap undefined for the global object if necessary in the prologue

src/x87/full-codegen-x87.cc

Index: src/x87/full-codegen-x87.cc
diff --git a/src/x87/full-codegen-x87.cc b/src/x87/full-codegen-x87.cc
index 3a6edec82be993d679f2ddd75c34726a46a9d4d0..3dbb6d41b128b27ddce603a58aff3e7c49f83d38 100644
--- a/src/x87/full-codegen-x87.cc
+++ b/src/x87/full-codegen-x87.cc
@@ -114,7 +114,8 @@ void FullCodeGenerator::Generate() {
   // Sloppy mode functions and builtins need to replace the receiver with the
   // global proxy when called as functions (without an explicit receiver
   // object).
-  if (is_sloppy(info->language_mode()) && !info->is_native()) {
+  if (is_sloppy(info->language_mode()) && !info->is_native() &&
+      info->MayUseThis()) {
     Label ok;
     // +1 for return address.
     int receiver_offset = (info->scope()->num_parameters() + 1) * kPointerSize;