Reimplement Maps and Sets in JS

src/mips64/code-stubs-mips64.cc

Index: src/mips64/code-stubs-mips64.cc
diff --git a/src/mips64/code-stubs-mips64.cc b/src/mips64/code-stubs-mips64.cc
index ae99442316ace55f9b90a10f5b7786a239751d0e..34a61ff037e6066042c197e6b168366ff7e94402 100644
--- a/src/mips64/code-stubs-mips64.cc
+++ b/src/mips64/code-stubs-mips64.cc
@@ -1103,16 +1103,6 @@ void CEntryStub::Generate(MacroAssembler* masm) {
               masm->InstructionsGeneratedSince(&find_ra));
   }
 
-  // Runtime functions should not return 'the hole'.  Allowing it to escape may
-  // lead to crashes in the IC code later.
-  if (FLAG_debug_code) {
-    Label okay;
-    __ LoadRoot(a4, Heap::kTheHoleValueRootIndex);
-    __ Branch(&okay, ne, v0, Operand(a4));
-    __ stop("The hole escaped");
-    __ bind(&okay);
-  }
-
   // Check result for exception sentinel.
   Label exception_returned;
   __ LoadRoot(a4, Heap::kExceptionRootIndex);