[runtime] Fix ES6 9.2.1 [[Call]] when encountering a classConstructor.

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index dfe501eb63edd430f85bc39b985ab9fefae8b9fe..7ec50ba363025210aa48e441e42d4f6803c0b0c2 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -1563,8 +1563,29 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm) {
 
   Label convert, convert_global_proxy, convert_to_object, done_convert;
   __ AssertFunction(a1);
-  // TODO(bmeurer): Throw a TypeError if function's [[FunctionKind]] internal
-  // slot is "classConstructor".
+  __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
+
+  {
+    Label non_class_constructor;
+    // Check whether the current function is a classConstructor This only works
+    // since kClassConstructor is more than 1 bit away from the byte boundary in
+    // CompilerHints (note that compiler_hints is stored as smi on 32bit
+    // architectures)
+    STATIC_ASSERT((FunctionKind::kClassConstructor << kSmiTagSize) <
+                  (1 << kBitsPerByte));
+    __ lbu(a3,
+           FieldMemOperand(a2, SharedFunctionInfo::kFunctionKindByteOffset));
+    // Left-shift to account for smi storage in 32bits.
+    __ And(at, a3, Operand(FunctionKind::kClassConstructor << kSmiTagSize));
+    __ Branch(&non_class_constructor, eq, at, Operand(zero_reg));
+    // Step: 2, If we call a classConstructor Function throw a TypeError.
+    {
+      FrameScope frame(masm, StackFrame::INTERNAL);
+      __ CallRuntime(Runtime::kThrowConstructorNonCallableError, 0);
+    }
+    __ bind(&non_class_constructor);
+  }
+
   // Enter the context of the function; ToObject has to run in the function
   // context, and we also need to take the global proxy from the function
   // context in case of conversion.
@@ -1572,7 +1593,6 @@ void Builtins::Generate_CallFunction(MacroAssembler* masm) {
   STATIC_ASSERT(SharedFunctionInfo::kNativeByteOffset ==
                 SharedFunctionInfo::kStrictModeByteOffset);
   __ lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
-  __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
   // We need to convert the receiver for non-native sloppy mode functions.
   __ lbu(a3, FieldMemOperand(a2, SharedFunctionInfo::kNativeByteOffset));
   __ And(at, a3, Operand((1 << SharedFunctionInfo::kNativeBitWithinByte) |