Adding simple test for trace correctness

Checks that the trace now includes the class as part of the trace. Note
this check doesn't precisly validate the trace - but would have caught
the original bug.

Author: thk123

regression/cbmc/trace_class_identifier/TestGenTest.class

@@ -0,0 +1,7 @@
+public class TestGenTest
+{
+  public void f()
+  {
+    int a = 4;
+  }
+}

regression/cbmc/trace_class_identifier/TestGenTest.java

@@ -0,0 +1,8 @@
+CORE
+TestGenTest.class
+--function TestGenTest.f --trace --cover location --json-ui
+"data": "java::TestGenTest",$
+^EXIT=0$
+^SIGNAL=0$
+--
+^warning: ignoring