How to customize the name of an enumeration value, using the extension `enumvalue_customname ` seems unable to complete.

[MicroOps-cn]

This is the official test case:

protobuf/test/enumcustomname/enumcustomname.proto

Lines 38 to 45 in b03c65e

	enum MyEnum {
	option (gogoproto.enum_customname) = "MyCustomEnum";
	// The following field will take on the custom name and the prefix, joined
	// by an underscore.
	A = 0 [(gogoproto.enumvalue_customname) = "MyBetterNameA"];
	B = 1; // Should be MyCustomEnum_B
	}

protobuf/test/enumcustomname/enumcustomname.pb.go

Lines 31 to 47 in b03c65e

	const (
	// The following field will take on the custom name and the prefix, joined
	// by an underscore.
	MyCustomEnum_MyBetterNameA MyCustomEnum = 0
	MyCustomEnum_B MyCustomEnum = 1
	)
	var MyCustomEnum_name = map[int32]string{
	0: "A",
	1: "B",
	}
	var MyCustomEnum_value = map[string]int32{
	"A": 0,
	"B": 1,
	}

In the above example, line 43 in the "enumcustomname.proto" file uses the "enumvalue_customname" extension to customize the name of the enumeration value. In the 34th page of "enumcustomname.pb.go", the variable name is the name of a custom enumeration value. However, lines 39 and 44 have not been replaced with custom enumeration names.
But I think the generated code should be like this:

const (
	// The following field will take on the custom name and the prefix, joined
	// by an underscore.
	MyCustomEnum_MyBetterNameA MyCustomEnum = 0
	MyCustomEnum_B             MyCustomEnum = 1
)

var MyCustomEnum_name = map[int32]string{
	0: "MyBetterNameA",
	1: "B",
}

var MyCustomEnum_value = map[string]int32{
	"MyBetterNameA": 0,
	"B": 1,
}