Enable constant pool support.

src/ppc/frames-ppc.cc

Index: src/ppc/frames-ppc.cc
diff --git a/src/ppc/frames-ppc.cc b/src/ppc/frames-ppc.cc
index 00af7c9b01551c52de57b7729dff129da4d5ca09..3fc44a0c74bd605faa0c8c01bf36f54e0049818a 100644
--- a/src/ppc/frames-ppc.cc
+++ b/src/ppc/frames-ppc.cc
@@ -21,16 +21,16 @@ namespace internal {
 Register JavaScriptFrame::fp_register() { return v8::internal::fp; }
 Register JavaScriptFrame::context_register() { return cp; }
 Register JavaScriptFrame::constant_pool_pointer_register() {
-  UNREACHABLE();
-  return no_reg;
+  DCHECK(FLAG_enable_embedded_constant_pool);
+  return kConstantPoolRegister;
 }
 
 
 Register StubFailureTrampolineFrame::fp_register() { return v8::internal::fp; }
 Register StubFailureTrampolineFrame::context_register() { return cp; }
 Register StubFailureTrampolineFrame::constant_pool_pointer_register() {
-  UNREACHABLE();
-  return no_reg;
+  DCHECK(FLAG_enable_embedded_constant_pool);
+  return kConstantPoolRegister;
 }