Revert of Replace all remaining Oddball checks with new function

src/full-codegen/ppc/full-codegen-ppc.cc

Index: src/full-codegen/ppc/full-codegen-ppc.cc
diff --git a/src/full-codegen/ppc/full-codegen-ppc.cc b/src/full-codegen/ppc/full-codegen-ppc.cc
index 052f085ee68a50fb303181e39100469d85c69a35..8d9e49f83839740b04a8130718c8e7d3684b92a7 100644
--- a/src/full-codegen/ppc/full-codegen-ppc.cc
+++ b/src/full-codegen/ppc/full-codegen-ppc.cc
@@ -516,12 +516,11 @@
 void FullCodeGenerator::TestContext::Plug(Handle<Object> lit) const {
   codegen()->PrepareForBailoutBeforeSplit(condition(), true, true_label_,
                                           false_label_);
-  DCHECK(lit->IsNull(isolate()) || lit->IsUndefined(isolate()) ||
+  DCHECK(lit->IsNull() || lit->IsUndefined(isolate()) ||
          !lit->IsUndetectable());
-  if (lit->IsUndefined(isolate()) || lit->IsNull(isolate()) ||
-      lit->IsFalse(isolate())) {
+  if (lit->IsUndefined(isolate()) || lit->IsNull() || lit->IsFalse()) {
     if (false_label_ != fall_through_) __ b(false_label_);
-  } else if (lit->IsTrue(isolate()) || lit->IsJSObject()) {
+  } else if (lit->IsTrue() || lit->IsJSObject()) {
     if (true_label_ != fall_through_) __ b(true_label_);
   } else if (lit->IsString()) {
     if (String::cast(*lit)->length() == 0) {