Set the current context to the function's context when entering to LAP.

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index 7908ff70eb39260e8861e082d9d2c48f33ad4cdb..a5edf4aeae441e71591f5cccb473925ee8b6b8ea 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -2944,6 +2944,7 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   //  -- ...
   //  -- sp[(argc - 1)* 4]   : first argument
   //  -- sp[argc * 4]        : receiver
+  //  -- sp[(argc + 1)* 4]   : accessor_holder
   // -----------------------------------
 
   Register callee = a0;
@@ -2969,10 +2970,6 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
 
   // Save context, callee and call data.
   __ Push(context, callee, call_data);
-  if (!is_lazy()) {
-    // Load context from callee.
-    __ lw(context, FieldMemOperand(callee, JSFunction::kContextOffset));
-  }
 
   Register scratch = call_data;
   __ LoadRoot(scratch, Heap::kUndefinedValueRootIndex);
@@ -2982,6 +2979,20 @@ void CallApiCallbackStub::Generate(MacroAssembler* masm) {
   // Push isolate and holder.
   __ Push(scratch, holder);
 
+  // Enter a new context
+  if (is_lazy()) {
+    // Load context from accessor_holder
+    Register accessor_holder = context;
+    __ lw(accessor_holder,
+          MemOperand(sp, (FCA::kArgsLength + 1 + argc()) * kPointerSize));
+    __ lw(scratch, FieldMemOperand(accessor_holder, HeapObject::kMapOffset));
+    __ GetMapConstructor(scratch, scratch, context, callee);
+    __ lw(context, FieldMemOperand(scratch, JSFunction::kContextOffset));
+  } else {
+    // Load context from callee.
+    __ lw(context, FieldMemOperand(callee, JSFunction::kContextOffset));
+  }
+
   // Prepare arguments.
   __ mov(scratch, sp);