src/vs/workbench/contrib/tasks/common/problemMatcher.ts/AbstractLineMatcher/getSeverity
class AbstractLineMatcher:	private getSeverity(data: IProblemData): MarkerSeverity {
		let result: Severity | null = null;
		if (data.severity) {
			const value = data.severity;
			if (value) {
				result = Severity.fromValue(value);
				if (result === Severity.Ignore) {
					if (value === 'E') {
						result = Severity.Error;
					} else if (value === 'W') {
						result = Severity.Warning;
					} else if (value === 'I') {
						result = Severity.Info;
					} else if (Strings.equalsIgnoreCase(value, 'hint')) {
						result = Severity.Info;
					} else if (Strings.equalsIgnoreCase(value, 'note')) {
						result = Severity.Info;
					}
				}
			}
		}
		if (result === null || result === Severity.Ignore) {
			result = this.matcher.severity || Severity.Error;
		}
		return MarkerSeverity.fromSeverity(result);
	}