MIPS64: Fix 'Remove usages of Heap::NewSpaceStart and its external reference'.

Port f2a58593

Original commit message:
Replace the uses with proper page flag lookups.

BUG=chromium:581412
LOG=N
TEST=mjsunit/allocation-site-info

Review-Url: https://codereview.chromium.org/1989483002
Cr-Commit-Position: refs/heads/master@{#36289}

src/mips64/macro-assembler-mips64.cc

@@ -6967,14 +6967,14 @@ void MacroAssembler::TestJSArrayForAllocationMemento(Register receiver_reg,
   JumpIfNotInNewSpace(receiver_reg, scratch_reg, no_memento_found);
   // If the object is in new space, we need to check whether it is on the same
   // page as the current top.
-  Addu(scratch_reg, receiver_reg, Operand(kMementoEndOffset));
+  Daddu(scratch_reg, receiver_reg, Operand(kMementoEndOffset));
   Xor(scratch_reg, scratch_reg, Operand(new_space_allocation_top));
   And(scratch_reg, scratch_reg, Operand(~Page::kPageAlignmentMask));
   Branch(&top_check, eq, scratch_reg, Operand(zero_reg));
   // The object is on a different page than allocation top. Bail out if the
   // object sits on the page boundary as no memento can follow and we cannot
   // touch the memory following it.
-  Addu(scratch_reg, receiver_reg, Operand(kMementoEndOffset));
+  Daddu(scratch_reg, receiver_reg, Operand(kMementoEndOffset));
   Xor(scratch_reg, scratch_reg, Operand(receiver_reg));
   And(scratch_reg, scratch_reg, Operand(~Page::kPageAlignmentMask));
   Branch(no_memento_found, ne, scratch_reg, Operand(zero_reg));
@@ -6983,13 +6983,13 @@ void MacroAssembler::TestJSArrayForAllocationMemento(Register receiver_reg,
   // If top is on the same page as the current object, we need to check whether
   // we are below top.
   bind(&top_check);
-  Addu(scratch_reg, receiver_reg, Operand(kMementoEndOffset));
+  Daddu(scratch_reg, receiver_reg, Operand(kMementoEndOffset));
   li(at, Operand(new_space_allocation_top));
-  lw(at, MemOperand(at));
+  ld(at, MemOperand(at));
   Branch(no_memento_found, gt, scratch_reg, Operand(at));
   // Memento map check.
   bind(&map_check);
-  lw(scratch_reg, MemOperand(receiver_reg, kMementoMapOffset));
+  ld(scratch_reg, MemOperand(receiver_reg, kMementoMapOffset));
   Branch(no_memento_found, ne, scratch_reg,
          Operand(isolate()->factory()->allocation_memento_map()));
 }