Provide baseline GC version.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 591012805b0c8c44d3009c2deb5ed80ceeae81cb..5871d264c942910f5f5e0bbe23d83731324c3622 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -795,6 +795,7 @@ MaybeObject* Object::GetProperty(String* key, PropertyAttributes* attributes) {
 #define WRITE_BARRIER(object, offset) \
   Heap::RecordWrite(object->address(), offset);
 
+#ifndef BASELINE_GC
 // CONDITIONAL_WRITE_BARRIER must be issued after the actual
 // write due to the assert validating the written value.
 #define CONDITIONAL_WRITE_BARRIER(object, offset, mode) \
@@ -807,6 +808,9 @@ MaybeObject* Object::GetProperty(String* key, PropertyAttributes* attributes) {
            Page::FromAddress(object->address())->           \
                IsRegionDirty(object->address() + offset));  \
   }
+#else
+#define CONDITIONAL_WRITE_BARRIER(object, offset, mode)
+#endif
 
 #define READ_DOUBLE_FIELD(p, offset) \
   (*reinterpret_cast<double*>(FIELD_ADDR(p, offset)))
@@ -1016,7 +1020,7 @@ void MapWord::ClearOverflow() {
   value_ &= ~kOverflowMask;
 }
 
-
+#ifndef BASELINE_GC
 MapWord MapWord::EncodeAddress(Address map_address, int offset) {
   // Offset is the distance in live bytes from the first live object in the
   // same page. The offset between two objects in the same page should not
@@ -1070,7 +1074,7 @@ MapWord MapWord::FromEncodedAddress(Address address) {
 Address MapWord::ToEncodedAddress() {
   return reinterpret_cast<Address>(value_);
 }
-
+#endif
 
 #ifdef DEBUG
 void HeapObject::VerifyObjectField(int offset) {