go v1.17.x breaks the (os.exec) Cmd.Start() functionality on Windows

[techema]

What version of Go are you using (go version)?

$ go version
1.17.2

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
set GO111MODULE=
set GOARCH=amd64
set GOBIN=
set GOCACHE=C:\Users\Administrator\AppData\Local\go-build
set GOENV=C:\Users\Administrator\AppData\Roaming\go\env
set GOEXE=.exe
set GOEXPERIMENT=
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOINSECURE=
set GOMODCACHE=C:\Users\Administrator\go\pkg\mod
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=C:\Users\Administrator\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 GOVCS=
set GOVERSION=go1.17.2
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=C:\test\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\ADMINI~1\AppData\Local\Temp\go-build2858189327=/tmp/go-build -gno-record-gcc-switches

What did you do?

exec.Command().Start() has been broken on Windows by v1.17.

The following code runs properly with go 1.16.5:

	cmd := exec.Command("C:\\Windows\\System32\\timeout.exe"", "30")
	cmd.SysProcAttr = &syscall.SysProcAttr{NoInheritHandles: true, CreationFlags: 16/*CREATE_NEW_CONSOLE*/}
	err := cmd.Start()
	if err != nil {
		fmt.Println(err)
	}

However, it fails on 1.17.2 (and 1.17.1).

&fs.PathError{Op:"fork/exec", Path:"C:\\WINDOWS\\System32\\timeout.exe", Err:0x57}

I have traced it to the newly introduced ProcThreadAttributeList parameter to the _STARTUPINFOEXW
If I remove the _EXTENDED_STARTUPINFO_PRESENT flag before the call to CreateProcess, then the process is properly started.
I can also see that si.ProcThreadAttributeList gets initialized for max 2 attributes, but then they may or may not be set (depending on some conditions). then, the _EXTENDED_STARTUPINFO_PRESENT is used regardless if those attributes are set or not. I think that the flag should only be set if the attributes are set.
But furthermore, since I do not want the ParentProcess to be set, I even tried to initialize the list with max 1 attribute (and call the code for _PROC_THREAD_ATTRIBUTE_HANDLE_LIST); however, the execution still failed.

What did you expect to see?

No error, process properly started.

What did you see instead?

&fs.PathError{Op:"fork/exec", Path:"C:\\WINDOWS\\System32\\timeout.exe", Err:0x57} error

0x57 error code is "The parameter is invalid"

[seankhliao]

Duplicate of #48040
1.17 backport tracked in #48075