Clean up dead code after spread desugaring

src/full-codegen/mips64/full-codegen-mips64.cc

Index: src/full-codegen/mips64/full-codegen-mips64.cc
diff --git a/src/full-codegen/mips64/full-codegen-mips64.cc b/src/full-codegen/mips64/full-codegen-mips64.cc
index 44dd791a59b1ca1037b37886a9139241774a8a6e..1f60d0703d3ed4645c774bceed809dc326880b5d 100644
--- a/src/full-codegen/mips64/full-codegen-mips64.cc
+++ b/src/full-codegen/mips64/full-codegen-mips64.cc
@@ -1716,7 +1716,7 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
   int array_index = 0;
   for (; array_index < length; array_index++) {
     Expression* subexpr = subexprs->at(array_index);
-    if (subexpr->IsSpread()) break;
+    DCHECK(!subexpr->IsSpread());
 
     // If the subexpression is a literal or a simple materialized literal it
     // is already set in the cloned array.
@@ -1753,14 +1753,9 @@ void FullCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) {
     Expression* subexpr = subexprs->at(array_index);
 
     __ Push(v0);
-    if (subexpr->IsSpread()) {
-      VisitForStackValue(subexpr->AsSpread()->expression());
-      __ InvokeBuiltin(Context::CONCAT_ITERABLE_TO_ARRAY_BUILTIN_INDEX,
-                       CALL_FUNCTION);
-    } else {
-      VisitForStackValue(subexpr);
-      __ CallRuntime(Runtime::kAppendElement);
-    }
+    DCHECK(!subexpr->IsSpread());
+    VisitForStackValue(subexpr);
+    __ CallRuntime(Runtime::kAppendElement);
 
     PrepareForBailoutForId(expr->GetIdForElement(array_index), NO_REGISTERS);
   }