Result parameter names are not retained for generated injectors

[ghost]

Describe the bug

Result parameter names are not retained for generated injectors. Result parameters can be useful for tools like gopls and IDEs for suggesting variable names, generating code, and can help provide semantic context to callers of injectors.

To Reproduce

Create an injector that has a result parameter name. Call wire. Observe that the result parameter name is not copied to the generated injector.

Minimum Reproduction

Input:

// wire.go
package main

import (
	"github.com/google/wire"
)

func provide() (string) {
	return "provided"
}

func Inject() (val string) {
	panic(wire.Build(provide))
}

Output:

// Code generated by Wire. DO NOT EDIT.

//go:generate wire
//+build !wireinject

package main

// Injectors from wire.go:

func Inject() string {
	string2 := provide()
	return string2
}

// wire.go:

func provide() string {
	return "provided"
}

Expected behavior

I would expect the result parameter name to be copied if it exists.

// ... 
func Inject() (val string) {
	string2 := provide()
	return string2
}
// ... 

Version

github.com/google/wire v0.4.0

Additional Information

$ go version
go version go1.14 windows/amd64

go env Output

$ go env
set GO111MODULE=on
set GOARCH=amd64
set GOBIN=C:\Users\jense\bin
set GOCACHE=C:\Users\jense\AppData\Local\go-build
set GOENV=C:\Users\jense\AppData\Roaming\go\env
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\jense\go
set GOPRIVATE=
set GOPROXY=https://proxy.golang.org,direct
set GOROOT=c:\go
set GOSUMDB=sum.golang.org
set GOTMPDIR=
set GOTOOLDIR=c:\go\pkg\tool\windows_amd64
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=C:\Users\jense\go.mod
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=C:\Users\jense\AppData\Local\Temp\go-build761127338=/tmp/go-build -gno-record-gcc-switches
GOROOT/bin/go version: go version go1.14 windows/amd64
GOROOT/bin/go tool compile -V: compile version go1.14