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

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 b80a2b24fd5290b888052f3e11e2088f633ce00d..27de1dcecb39cabe0595b73a8e6b16c8a872f7e5 100644
--- a/src/ppc/full-codegen-ppc.cc
+++ b/src/ppc/full-codegen-ppc.cc
@@ -123,7 +123,8 @@ 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;
     int receiver_offset = info->scope()->num_parameters() * kPointerSize;
     __ LoadP(r5, MemOperand(sp, receiver_offset), r0);