go: update from 1.7.4 to 1.8

Release notes of new release: https://golang.org/doc/go1.8
The patch adding support of PKG_CONFIG is not needed anymore:
it was merged to upstream: https://github.com/golang/go/commit/5dcb31b2d55

plugins/go/go-1-fixes.patch

@@ -1,107 +0,0 @@
-This file is part of MXE. See LICENSE.md for licensing information.
-
-Contains ad hoc patches for cross building.
-
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Boris Nagaev <bnagaev@gmail.com>
-Date: Sat, 25 Jun 2016 13:51:06 +0200
-Subject: [PATCH] cgo: add environment variable override for pkg-config
-
-Allow overriding default name of `pkg-config` utility via
-environment variable PKG_CONFIG (same as used by autoconf
-pkg.m4 macros). This facilitates easy cross-compilation of cgo
-code.
-
-Original patch against Go <= 1.4 was written by
-xnox_canonical <dimitri.ledkov@canonical.com> in 2014.
-Source: https://codereview.appspot.com/104960043/
-
-Rebased against Go 1.6.2 by Boris Nagaev <bnagaev@gmail.com>.
-
-diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
-index 1111111..2222222 100644
---- a/src/cmd/dist/build.go
-+++ b/src/cmd/dist/build.go
-@@ -41,6 +41,7 @@ var (
- 	defaultldflags   string
- 	defaultcxxtarget string
- 	defaultcctarget  string
-+	defaultpkgconfigtarget  string
- 	rebuildall       bool
- 	defaultclang     bool
- 
-@@ -203,6 +204,12 @@ func xinit() {
- 	}
- 	defaultcxxtarget = b
- 
-+	b = os.Getenv("PKG_CONFIG")
-+	if b == "" {
-+		b = "pkg-config"
-+	}
-+	defaultpkgconfigtarget = b
-+
- 	// For tools being invoked but also for os.ExpandEnv.
- 	os.Setenv("GO386", go386)
- 	os.Setenv("GOARCH", goarch)
-diff --git a/src/cmd/dist/buildgo.go b/src/cmd/dist/buildgo.go
-index 1111111..2222222 100644
---- a/src/cmd/dist/buildgo.go
-+++ b/src/cmd/dist/buildgo.go
-@@ -15,6 +15,7 @@ import "fmt"
- //	package main
- //	const defaultCC = <defaultcc>
- //	const defaultCXX = <defaultcxx>
-+//	const defaultPkgConfig = <defaultpkgconfig>
- //
- // It is invoked to write cmd/go/zdefaultcc.go
- // but we also write cmd/cgo/zdefaultcc.go
-@@ -27,8 +28,9 @@ func mkzdefaultcc(dir, file string) {
- 			"package main\n"+
- 			"\n"+
- 			"const defaultCC = `%s`\n"+
--			"const defaultCXX = `%s`\n",
--		defaultcctarget, defaultcxxtarget)
-+			"const defaultCXX = `%s`\n"+
-+			"const defaultPkgConfig = `%s`\n",
-+		defaultcctarget, defaultcxxtarget, defaultpkgconfigtarget)
- 
- 	writefile(out, file, writeSkipSame)
- 
-diff --git a/src/cmd/go/build.go b/src/cmd/go/build.go
-index 1111111..2222222 100644
---- a/src/cmd/go/build.go
-+++ b/src/cmd/go/build.go
-@@ -1575,13 +1575,19 @@ func (b *builder) build(a *action) (err error) {
- 	return nil
- }
- 
-+// pkgconfigCmd returns a pkg-config binary name
-+// defaultPkgConfig is defined in zdefaultcc.go, written by cmd/dist.
-+func (b *builder) pkgconfigCmd() string {
-+   return envList("PKG_CONFIG", defaultPkgConfig)[0]
-+}
-+
- // Calls pkg-config if needed and returns the cflags/ldflags needed to build the package.
- func (b *builder) getPkgConfigFlags(p *Package) (cflags, ldflags []string, err error) {
- 	if pkgs := p.CgoPkgConfig; len(pkgs) > 0 {
- 		var out []byte
--		out, err = b.runOut(p.Dir, p.ImportPath, nil, "pkg-config", "--cflags", pkgs)
-+		out, err = b.runOut(p.Dir, p.ImportPath, nil, b.pkgconfigCmd(), "--cflags", pkgs)
- 		if err != nil {
--			b.showOutput(p.Dir, "pkg-config --cflags "+strings.Join(pkgs, " "), string(out))
-+			b.showOutput(p.Dir, b.pkgconfigCmd()+" --cflags "+strings.Join(pkgs, " "), string(out))
- 			b.print(err.Error() + "\n")
- 			err = errPrintedOutput
- 			return
-@@ -1589,9 +1595,9 @@ func (b *builder) getPkgConfigFlags(p *Package) (cflags, ldflags []string, err e
- 		if len(out) > 0 {
- 			cflags = strings.Fields(string(out))
- 		}
--		out, err = b.runOut(p.Dir, p.ImportPath, nil, "pkg-config", "--libs", pkgs)
-+		out, err = b.runOut(p.Dir, p.ImportPath, nil, b.pkgconfigCmd(), "--libs", pkgs)
- 		if err != nil {
--			b.showOutput(p.Dir, "pkg-config --libs "+strings.Join(pkgs, " "), string(out))
-+			b.showOutput(p.Dir, b.pkgconfigCmd()+" --libs "+strings.Join(pkgs, " "), string(out))
- 			b.print(err.Error() + "\n")
- 			err = errPrintedOutput
- 			return

plugins/go/go.mk

@@ -4,8 +4,8 @@ PKG             := go
 $(PKG)_WEBSITE  := https://golang.org/
 $(PKG)_OWNER    := https://github.com/starius
 $(PKG)_IGNORE   :=
-$(PKG)_VERSION  := 1.7.4
-$(PKG)_CHECKSUM := 4c189111e9ba651a2bb3ee868aa881fab36b2f2da3409e80885ca758a6b614cc
+$(PKG)_VERSION  := 1.8
+$(PKG)_CHECKSUM := 406865f587b44be7092f206d73fc1de252600b79b3cacc587b74b5ef5c623596
 $(PKG)_SUBDIR   := go
 $(PKG)_FILE     := go$($(PKG)_VERSION).src.tar.gz
 $(PKG)_URL      := https://storage.googleapis.com/golang/$($(PKG)_FILE)