unix: factor out mkmerge into a proper package
Factor mkmerge.go and mkmerge_test.go into package internal/mkmerge.
Due to ignore constraints, mkmerge_test.go wasn't run by the Go
builders and failing tests were unnoticed.
Factoring mkmerge into its own package and removing ignore constraints
makes the tests run automatically by the Go builders.
Fixes golang/go#49484
Change-Id: I56a0b7220e40d1d7e5193490cb547cad4202f9ac
Reviewed-on: https://go-review.googlesource.com/c/sys/+/363334
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>
Trust: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
diff --git a/unix/zsyscall_linux.go b/unix/zsyscall_linux.go
index 4f5da1f..fe6c232 100644
--- a/unix/zsyscall_linux.go
+++ b/unix/zsyscall_linux.go
@@ -1,4 +1,4 @@
-// Code generated by mkmerge.go; DO NOT EDIT.
+// Code generated by mkmerge; DO NOT EDIT.
//go:build linux
// +build linux
