Run go mod tidy before vendoring in compilecheck. (#1620)

etc/compile_check.sh

@@ -20,19 +20,18 @@ function compile_check {
 	# Change the directory to the compilecheck test directory.
 	cd ${COMPILE_CHECK_DIR}
 
+	# If the Go version is 1.15 or greater, then run "go mod tidy".
+	MACHINE_VERSION=`${GC} version | { read _ _ v _; echo ${v#go}; }`
+	if [ $(version $MACHINE_VERSION) -ge $(version 1.15) ]; then
+		go mod tidy
+	fi
+
 	# Test vendoring
 	go mod vendor
 	${GC} build -mod=vendor
 
 	rm -rf vendor
 
-	MACHINE_VERSION=`${GC} version | { read _ _ v _; echo ${v#go}; }`
-
-	# If the version is not 1.13, then run "go mod tidy"
-	if [ $(version $MACHINE_VERSION) -ge $(version 1.15) ]; then
-		go mod tidy
-	fi
-
 	# Check simple build.
 	${GC} build ./...