os.Args should remove test flag value also.

[ijajmulani]

bincover/instrument_bin.go

Lines 68 to 80 in b97fcf5

	for _, arg := range os.Args {
	if !strings.HasPrefix(arg, "-test.") && !strings.HasPrefix(arg, "-args-file") {
	parsedArgs = append(parsedArgs, arg)
	}
	}
	if len(*argsFilename) > 0 {
	customArgs, err := parseCustomArgs()
	if err != nil {
	panic(err)
	}
	parsedArgs = append(parsedArgs, customArgs...)
	}
	os.Args = parsedArgs

Above code should remove test.* args value from os.Args.

e.g. if I run binary with below command
./mybinary.test -test.cpuprofile b.cov customargs

in the end OS.Args contains b.cov and customargs. Since b.cov is value -test.* argument it should not include in the end.