os, syscall: Seek on pipe on windows doesn't return ESPIPE

[hirochachacha]

Please answer these questions before submitting your issue. Thanks!

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

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

What did you do?

If possible, provide a recipe for reproducing the error.
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According to http://pubs.opengroup.org/onlinepubs/009695399/functions/lseek.html:
lseek returns ESPIPE on pipe.

However, current implementation use EPIPE instead.

go/src/syscall/syscall_windows.go

Lines 350 to 352 in eaa198f

	if ft == FILE_TYPE_PIPE {
	return 0, EPIPE
	}

What did you expect to see?

ESPIPE

What did you see instead?

EPIPE

[ianlancetaylor]

It's hard to get too excited about this, since we made up EPIPE anyhow for Windows. But if you want to send a patch I suppose it's OK with me.

[gopherbot]

CL https://golang.org/cl/41311 mentions this issue.