[gcc r12-8763] libgo: make runtime.Version return a meaningful string

[Ian Lance Taylor <ian@gcc.gnu.org>]

https://gcc.gnu.org/g:23605c6a4eef5ca8ecb64d7006b60aeed241c29c

commit r12-8763-g23605c6a4eef5ca8ecb64d7006b60aeed241c29c
Author: Ian Lance Taylor <iant@golang.org>
Date:   Tue Sep 13 13:11:17 2022 -0700

    libgo: make runtime.Version return a meaningful string
    
    For golang/go#51850
    Fixes PR go/106747
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/414734

Diff:
---
 libgo/Makefile.am          |  1 +
 libgo/Makefile.in          |  1 +
 libgo/go/runtime/extern.go | 10 ----------
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/libgo/Makefile.am b/libgo/Makefile.am
index a5d4b6a3525..b03e6553e90 100644
--- a/libgo/Makefile.am
+++ b/libgo/Makefile.am
@@ -568,6 +568,7 @@ s-goroot: Makefile
 	rm -f goroot.go.tmp
 	echo "package runtime" > goroot.go.tmp
 	echo 'var defaultGOROOT = `$(prefix)`' >> goroot.go.tmp
+	echo 'var buildVersion = `'`cat $(srcdir)/VERSION | sed 1q`' '`$(GOC) --version | sed 1q`'`' >> goroot.go.tmp
 	$(SHELL) $(srcdir)/mvifdiff.sh goroot.go.tmp goroot.go
 	$(STAMP) $@
 
diff --git a/libgo/Makefile.in b/libgo/Makefile.in
index 22f48a52938..16ed62a82ed 100644
--- a/libgo/Makefile.in
+++ b/libgo/Makefile.in
@@ -2780,6 +2780,7 @@ s-goroot: Makefile
 	rm -f goroot.go.tmp
 	echo "package runtime" > goroot.go.tmp
 	echo 'var defaultGOROOT = `$(prefix)`' >> goroot.go.tmp
+	echo 'var buildVersion = `'`cat $(srcdir)/VERSION | sed 1q`' '`$(GOC) --version | sed 1q`'`' >> goroot.go.tmp
 	$(SHELL) $(srcdir)/mvifdiff.sh goroot.go.tmp goroot.go
 	$(STAMP) $@
 
diff --git a/libgo/go/runtime/extern.go b/libgo/go/runtime/extern.go
index a371d9c0ee0..8e226147965 100644
--- a/libgo/go/runtime/extern.go
+++ b/libgo/go/runtime/extern.go
@@ -231,16 +231,6 @@ func GOROOT() string {
 	return defaultGOROOT
 }
 
-// buildVersion is the Go tree's version string at build time.
-//
-// If any GOEXPERIMENTs are set to non-default values, it will include
-// "X:<GOEXPERIMENT>".
-//
-// This is set by the linker.
-//
-// This is accessed by "go version <binary>".
-var buildVersion string
-
 // Version returns the Go tree's version string.
 // It is either the commit hash and date at the time of the build or,
 // when possible, a release tag like "go1.3".