Fix object initialization when slack tracking for it's map is still enabled.

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 4a5a386fa0f7cbf09eb0324bad52521f127c74c0..b255ceb8fd589635519b5da065e74df9633f868b 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -3347,28 +3347,25 @@ void MacroAssembler::Allocate(int object_size,
 }
 
 
-void MacroAssembler::Allocate(Register object_size,
-                              Register result,
-                              Register scratch1,
-                              Register scratch2,
-                              Label* gc_required,
-                              AllocationFlags flags) {
+void MacroAssembler::Allocate(Register object_size, Register result,
+                              Register result_end, Register scratch1,
+                              Label* gc_required, AllocationFlags flags) {
   if (!FLAG_inline_new) {
     if (emit_debug_code()) {
       // Trash the registers to simulate an allocation failure.
       li(result, 0x7091);
       li(scratch1, 0x7191);
-      li(scratch2, 0x7291);
+      li(result_end, 0x7291);
     }
     jmp(gc_required);
     return;
   }
 
   DCHECK(!result.is(scratch1));
-  DCHECK(!result.is(scratch2));
-  DCHECK(!scratch1.is(scratch2));
+  DCHECK(!result.is(result_end));
+  DCHECK(!scratch1.is(result_end));
   DCHECK(!object_size.is(t9));
-  DCHECK(!scratch1.is(t9) && !scratch2.is(t9) && !result.is(t9));
+  DCHECK(!scratch1.is(t9) && !result_end.is(t9) && !result.is(t9));
 
   // Check relative positions of allocation top and limit addresses.
   // ARM adds additional checks to make sure the ldm instruction can be
@@ -3408,14 +3405,14 @@ void MacroAssembler::Allocate(Register object_size,
     // 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(kPointerAlignment * 2 == kDoubleAlignment);
-    And(scratch2, result, Operand(kDoubleAlignmentMask));
+    And(result_end, result, Operand(kDoubleAlignmentMask));
     Label aligned;
-    Branch(&aligned, eq, scratch2, Operand(zero_reg));
+    Branch(&aligned, eq, result_end, Operand(zero_reg));
     if ((flags & PRETENURE) != 0) {
       Branch(gc_required, Ugreater_equal, result, Operand(t9));
     }
-    li(scratch2, Operand(isolate()->factory()->one_pointer_filler_map()));
-    sw(scratch2, MemOperand(result));
+    li(result_end, Operand(isolate()->factory()->one_pointer_filler_map()));
+    sw(result_end, MemOperand(result));
     Addu(result, result, Operand(kDoubleSize / 2));
     bind(&aligned);
   }
@@ -3424,19 +3421,19 @@ void MacroAssembler::Allocate(Register object_size,
   // to calculate the new top. Object size may be in words so a shift is
   // required to get the number of bytes.
   if ((flags & SIZE_IN_WORDS) != 0) {
-    sll(scratch2, object_size, kPointerSizeLog2);
-    Addu(scratch2, result, scratch2);
+    sll(result_end, object_size, kPointerSizeLog2);
+    Addu(result_end, result, result_end);
   } else {
-    Addu(scratch2, result, Operand(object_size));
+    Addu(result_end, result, Operand(object_size));
   }
-  Branch(gc_required, Ugreater, scratch2, Operand(t9));
+  Branch(gc_required, Ugreater, result_end, Operand(t9));
 
   // Update allocation top. result temporarily holds the new top.
   if (emit_debug_code()) {
-    And(t9, scratch2, Operand(kObjectAlignmentMask));
+    And(t9, result_end, Operand(kObjectAlignmentMask));
     Check(eq, kUnalignedAllocationInNewSpace, t9, Operand(zero_reg));
   }
-  sw(scratch2, MemOperand(topaddr));
+  sw(result_end, MemOperand(topaddr));
 
   // Tag object if requested.
   if ((flags & TAG_OBJECT) != 0) {