PPC: Reland "Merge old data and pointer space."

src/ppc/macro-assembler-ppc.cc

Index: src/ppc/macro-assembler-ppc.cc
diff --git a/src/ppc/macro-assembler-ppc.cc b/src/ppc/macro-assembler-ppc.cc
index bbc78dc6c4bb7de8726db9d691b3837a7fb61491..bfca9b36506e7b7a2b6548dd988eef649a549627 100644
--- a/src/ppc/macro-assembler-ppc.cc
+++ b/src/ppc/macro-assembler-ppc.cc
@@ -1368,7 +1368,6 @@ void MacroAssembler::Allocate(int object_size, Register result,
   if ((flags & DOUBLE_ALIGNMENT) != 0) {
     // Align the next allocation. Storing the filler map without checking top is
     // safe in new-space because the limit of the heap is aligned there.
-    DCHECK((flags & PRETENURE_OLD_SPACE) == 0);
 #if V8_TARGET_ARCH_PPC64
     STATIC_ASSERT(kPointerAlignment == kDoubleAlignment);
 #else
@@ -1467,7 +1466,6 @@ void MacroAssembler::Allocate(Register object_size, Register result,
   if ((flags & DOUBLE_ALIGNMENT) != 0) {
     // Align the next allocation. Storing the filler map without checking top is
     // safe in new-space because the limit of the heap is aligned there.
-    DCHECK((flags & PRETENURE_OLD_SPACE) == 0);
 #if V8_TARGET_ARCH_PPC64
     STATIC_ASSERT(kPointerAlignment == kDoubleAlignment);
 #else