[builtins] Start refactoring the Apply builtin.

src/mips64/macro-assembler-mips64.cc

Index: src/mips64/macro-assembler-mips64.cc
diff --git a/src/mips64/macro-assembler-mips64.cc b/src/mips64/macro-assembler-mips64.cc
index df9dbdb74f59a5f32bd48ab32b6343f7fc7958b8..8935a15a349f4639d7372622c5a00a112752d956 100644
--- a/src/mips64/macro-assembler-mips64.cc
+++ b/src/mips64/macro-assembler-mips64.cc
@@ -6335,6 +6335,15 @@ void MacroAssembler::AssertSmi(Register object) {
   }
 }
 
+void MacroAssembler::AssertFixedArray(Register object) {
+  if (emit_debug_code()) {
+    STATIC_ASSERT(kSmiTag == 0);
+    SmiTst(object, t8);
+    Check(ne, kOperandIsASmiAndNotAFixedArray, t8, Operand(zero_reg));
+    GetObjectType(object, t8, t8);
+    Check(eq, kOperandIsNotAFixedArray, t8, Operand(FIXED_ARRAY_TYPE));
+  }
+}
 
 void MacroAssembler::AssertFunction(Register object) {
   if (emit_debug_code()) {