Always require exact maps.

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index 3381a5b7b6cd0d2d3997451a162bb01eb91d008d..cfe94effca7f7ab0195f14fae3d30bc5eb2d8e34 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -892,8 +892,7 @@ class MacroAssembler: public Assembler {
   // sequences branches to early_success.
   void CompareMap(Register obj,
                   Handle<Map> map,
-                  Label* early_success,
-                  CompareMapMode mode = REQUIRE_EXACT_MAP);
+                  Label* early_success);
 
   // Check if the map of an object is equal to a specified map and branch to
   // label if not. Skip the smi check if not required (object is known to be a
@@ -902,8 +901,7 @@ class MacroAssembler: public Assembler {
   void CheckMap(Register obj,
                 Handle<Map> map,
                 Label* fail,
-                SmiCheckType smi_check_type,
-                CompareMapMode mode = REQUIRE_EXACT_MAP);
+                SmiCheckType smi_check_type);
 
   // Check if the map of an object is equal to a specified map and branch to a
   // specified target if equal. Skip the smi check if not required (object is