Remove HFixedArrayBaseLength instruction and replace with regular HLoadNamedField.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index e68c722873f047c2831dc462e87890731b8a08fb..638eaa4e8b524ed4fb8c7668f24a81fe6ff733cb 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1716,13 +1716,6 @@ LInstruction* LChunkBuilder::DoClassOfTestAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoFixedArrayBaseLength(
-    HFixedArrayBaseLength* instr) {
-  LOperand* array = UseRegisterAtStart(instr->value());
-  return DefineAsRegister(new(zone()) LFixedArrayBaseLength(array));
-}
-
-
 LInstruction* LChunkBuilder::DoMapEnumLength(HMapEnumLength* instr) {
   LOperand* map = UseRegisterAtStart(instr->value());
   return DefineAsRegister(new(zone()) LMapEnumLength(map));