cmd/go: set environment LANG=C when getting compiler version

Compiler's version will not work well if gcc output have
different language. Like 'gcc -v', it may not output:
'gcc version xx.xx.x'

 Fixes #69221

Change-Id: I4adcea79dfaaf5853dfb6e718468f8530c67da6a
GitHub-Last-Rev: 069787c
GitHub-Pull-Request: #69223
Reviewed-on: https://go-review.googlesource.com/c/go/+/610215
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: DING HU <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>

Author: jokemanfire

src/cmd/go/internal/work/init.go

@@ -357,7 +357,9 @@ func compilerVersion() (version, error) {
 		compiler.err = func() error {
 			compiler.name = "unknown"
 			cc := os.Getenv("CC")
-			out, err := exec.Command(cc, "--version").Output()
+			cmd := exec.Command(cc, "--version")
+			cmd.Env = append(cmd.Environ(), "LANG=C")
+			out, err := cmd.Output()
 			if err != nil {
 				// Compiler does not support "--version" flag: not Clang or GCC.
 				return err
@@ -366,7 +368,9 @@ func compilerVersion() (version, error) {
 			var match [][]byte
 			if bytes.HasPrefix(out, []byte("gcc")) {
 				compiler.name = "gcc"
-				out, err := exec.Command(cc, "-v").CombinedOutput()
+				cmd := exec.Command(cc, "-v")
+				cmd.Env = append(cmd.Environ(), "LANG=C")
+				out, err := cmd.CombinedOutput()
 				if err != nil {
 					// gcc, but does not support gcc's "-v" flag?!
 					return err