[stubs] Simplify the non-function case of CallConstructStub.

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index 3876eb39f8ef1aa16a98f5db3511cef08d1546ad..a4724567ffaf00c6c6d1b276391ddeba06b62b77 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -3120,6 +3120,8 @@ void FullCodeGenerator::VisitCallNew(CallNew* expr) {
   CallConstructStub stub(isolate(), RECORD_CONSTRUCTOR_TARGET);
   __ Call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
   PrepareForBailoutForId(expr->ReturnId(), TOS_REG);
+  // Restore context register.
+  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
   context()->Plug(rax);
 }
 
@@ -3169,6 +3171,9 @@ void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
 
   RecordJSReturnSite(expr);
 
+  // Restore context register.
+  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+
   context()->Plug(rax);
 }
 
@@ -4081,9 +4086,10 @@ void FullCodeGenerator::EmitDefaultConstructorCallSuper(CallRuntime* expr) {
   CallConstructStub stub(isolate(), SUPER_CONSTRUCTOR_CALL);
   __ call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
 
-  __ Drop(1);
+  // Restore context register.
+  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
 
-  context()->Plug(result_register());
+  context()->DropAndPlug(1, rax);
 }