Add per-stage failure to Jenkins pipeline

.ci/Jenkinsfile

@@ -53,6 +53,7 @@ pipeline {
 	stages {
 		stage('Build Windows') {
 			steps {
+				catchError(buildResult: 'SUCCESS', stageResult: 'FAILURE') {
 					node('windows') {
 						gitClone()
 						windowsBuild()
@@ -60,9 +61,11 @@ pipeline {
 					}
 				}
 			}
+		}
 
 		stage('Build Linux') {
 			steps {
+				catchError(buildResult: 'SUCCESS', stageResult: 'FAILURE') {
 					node('debian') {
 						gitClone()
 						unixBuild()
@@ -70,6 +73,7 @@ pipeline {
 					}
 				}
 			}
+		}
 
 		/* If we're on the main jobs, trigger each of the downstream jobs. */
 		stage('Trigger downstream jobs') {