Make context register implicit for CallInterfaceDescriptors

src/mips/lithium-mips.h

Index: src/mips/lithium-mips.h
diff --git a/src/mips/lithium-mips.h b/src/mips/lithium-mips.h
index a527837d6144b1448037a4f16d84f3f811ae5914..82c5ffd29dac17df799d2da1db98b49739ae76a7 100644
--- a/src/mips/lithium-mips.h
+++ b/src/mips/lithium-mips.h
@@ -1810,8 +1810,12 @@ class LCallWithDescriptor final : public LTemplateResultInstruction<1> {
   LCallWithDescriptor(CallInterfaceDescriptor descriptor,
                       const ZoneList<LOperand*>& operands, Zone* zone)
       : descriptor_(descriptor),
-        inputs_(descriptor.GetRegisterParameterCount() + 1, zone) {
-    DCHECK(descriptor.GetRegisterParameterCount() + 1 == operands.length());
+        inputs_(descriptor.GetRegisterParameterCount() +
+                    kImplicitRegisterParameterCount,
+                zone) {
+    DCHECK(descriptor.GetRegisterParameterCount() +
+               kImplicitRegisterParameterCount ==
+           operands.length());
     inputs_.AddAll(operands, zone);
   }
 
@@ -1821,6 +1825,10 @@ class LCallWithDescriptor final : public LTemplateResultInstruction<1> {
 
   DECLARE_HYDROGEN_ACCESSOR(CallWithDescriptor)
 
+  // The target and context are passed as implicit parameters that are not
+  // explicitly listed in the descriptor.
+  static const int kImplicitRegisterParameterCount = 2;
+
  private:
   DECLARE_CONCRETE_INSTRUCTION(CallWithDescriptor, "call-with-descriptor")