GODRIVER-1876 Drop pre Go 1.10 workarounds (#779)

Author: benjirewis

.evergreen/config.yml

@@ -1592,14 +1592,6 @@ tasks:
         vars:
           MONGO_GO_DRIVER_COMPRESSOR: "snappy"
 
-  - name: go1.9-build
-    tags: ["compile-check"]
-    commands:
-      - func: run-make
-        vars:
-          targets: "build"
-          BUILD_ENV: "PATH=/opt/golang/go1.9/bin:$PATH GOROOT=/opt/golang/go1.9"
-
   - name: go1.10-build
     tags: ["compile-check"]
     commands:

bson/bson.go

@@ -7,8 +7,6 @@
 // Based on gopkg.in/mgo.v2/bson by Gustavo Niemeyer
 // See THIRD-PARTY-NOTICES for original license terms.
 
-// +build go1.9
-
 package bson // import "go.mongodb.org/mongo-driver/bson"
 
 import (

bson/bson_1_8.go

@@ -1011,7 +1011,7 @@ func addClientCertFromBytes(cfg *tls.Config, data []byte, keyPasswd string) (str
 					if err != nil {
 						return "", err
 					}
-					keyBytes, err = x509MarshalPKCS8PrivateKey(decrypted)
+					keyBytes, err = x509.MarshalPKCS8PrivateKey(decrypted)
 					if err != nil {
 						return "", err
 					}
@@ -1047,7 +1047,7 @@ func addClientCertFromBytes(cfg *tls.Config, data []byte, keyPasswd string) (str
 		return "", err
 	}
 
-	return x509CertSubject(crt), nil
+	return crt.Subject.String(), nil
 }
 
 func stringSliceContains(source []string, target string) bool {

mongo/options/clientoptions.go

@@ -446,5 +446,5 @@ func addClientCertFromFile(cfg *tls.Config, clientFile, keyPasswd string) (strin
 		return "", err
 	}
 
-	return x509CertSubject(crt), nil
+	return crt.Subject.String(), nil
 }