Special case the recording of constant pool entries in the slot buffer.

src/x64/assembler-x64-inl.h

Index: src/x64/assembler-x64-inl.h
diff --git a/src/x64/assembler-x64-inl.h b/src/x64/assembler-x64-inl.h
index 073fcbe8e944902ac096b63f91b976bd3acd1ea0..f2ec0290238f75718c7459a5d1c6d4ec8adc96d8 100644
--- a/src/x64/assembler-x64-inl.h
+++ b/src/x64/assembler-x64-inl.h
@@ -267,6 +267,12 @@ Address RelocInfo::target_address_address() {
 }
 
 
+Address RelocInfo::constant_pool_entry_address() {
+  UNREACHABLE();
+  return NULL;
+}
+
+
 int RelocInfo::target_address_size() {
   if (IsCodedSpecially()) {
     return Assembler::kSpecialTargetSize;