crypto/x509: this change modifies C.CopyPEMRoots to static function

Change-Id: Ic7997d1f747152afec78e8e439770166029f34ec
GitHub-Last-Rev: 6a07f25056c960dc8684cd6eac22cd3405a936c8
GitHub-Pull-Request: golang/go#36491
Reviewed-on: https://go-review.googlesource.com/c/go/+/214298
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/crypto/x509/root_cgo_darwin.go

@@ -159,7 +159,7 @@ static Boolean isRootCertificate(SecCertificateRef cert, CFErrorRef *errRef) {
 //
 // Note: The CFDataRef returned in pemRoots and untrustedPemRoots must
 // be released (using CFRelease) after we've consumed its content.
-int CopyPEMRoots(CFDataRef *pemRoots, CFDataRef *untrustedPemRoots, bool debugDarwinRoots) {
+static int CopyPEMRoots(CFDataRef *pemRoots, CFDataRef *untrustedPemRoots, bool debugDarwinRoots) {
 	int i;
 
 	if (debugDarwinRoots) {