Description of problem:
If user issues multi-value insert, Teiid throws NPE.

Sample code
PreparedStatement ps = con.prepareStatement("INSERT INTO Dvqe__c (InternalID__c,MatrixID__c) VALUES (?,?),(?,?),(?,?)");
ps.setInt(1, 1);
ps.setString(2, uniqueMatrixID + "01");
ps.setInt(3, 2);
ps.setString(4, uniqueMatrixID + "02");
ps.setInt(5, 3);
ps.setString(6, uniqueMatrixID + "03");
int uc = ps.executeUpdate();

Exception
14:12:39,934 ERROR [org.teiid.PROCESSOR] (Worker0_QueryProcessorQueue3) TEIID30019 Unexpected exception for request 7kiAJNRuK+I4.1: java.lang.NullPointerException
    at org.teiid.query.resolver.command.SetQueryResolver.checkSymbolTypes(SetQueryResolver.java:160) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.command.SetQueryResolver.resolveSetQuery(SetQueryResolver.java:86) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.command.SetQueryResolver.resolveCommand(SetQueryResolver.java:68) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.QueryResolver.resolveCommand(QueryResolver.java:273) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.command.SetQueryResolver.resolveCommand(SetQueryResolver.java:61) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.QueryResolver.resolveCommand(QueryResolver.java:273) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.command.InsertResolver.resolveProceduralCommand(InsertResolver.java:86) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.ProcedureContainerResolver.resolveCommand(ProcedureContainerResolver.java:143) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.QueryResolver.resolveCommand(QueryResolver.java:273) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.query.resolver.QueryResolver.resolveCommand(QueryResolver.java:127) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.Request.resolveCommand(Request.java:282) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.Request.generatePlan(Request.java:402) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.PreparedStatementRequest.generatePlan(PreparedStatementRequest.java:119) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.Request.processRequest(Request.java:470) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.PreparedStatementRequest.processRequest(PreparedStatementRequest.java:294) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.RequestWorkItem.processNew(RequestWorkItem.java:642) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.RequestWorkItem.process(RequestWorkItem.java:337) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.AbstractWorkItem.run(AbstractWorkItem.java:51) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.RequestWorkItem.run(RequestWorkItem.java:274) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.DQPWorkContext.runInContext(DQPWorkContext.java:276) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.ThreadReuseExecutor$RunnableWrapper.run(ThreadReuseExecutor.java:119) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at org.teiid.dqp.internal.process.ThreadReuseExecutor$3.run(ThreadReuseExecutor.java:210) [teiid-engine-8.12.5.redhat-8.jar:8.12.5.redhat-8]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0-internal]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0-internal]
    at java.lang.Thread.run(Thread.java:744) [rt.jar:1.8.0-internal]