Add tests

com.oracle.truffle.r.test/tests/pgsql/QueryCallFunction.R

+dol_to_euro = function (dol) dol * 89 / 100
+emp = new.table("emp", "PostgreSQL", "postgre.config", "public")
+minsalary = 2500
+q3 = select(function (x) { res = new.env(); res$empno = x$empno; res$ename = x$ename;
+              res$salary = dol_to_euro(x$sal); res },
+     where(function (x) x$sal >= minsalary,
+     from(emp)))
+results3 = query.force(q3)
+for (r in results3) { print (sprintf("%d, %s, %d", r$empno, r$ename, r$salary)) }

com.oracle.truffle.r.test/tests/pgsql/QueryCallFunctionWithDeps.R

+dol_to_euro = function (dol) dol * 89 / 100
+dol_to_euro2 = dol_to_euro
+
+emp = new.table("emp", "PostgreSQL", "postgre.config", "public")
+minsalary = 2500
+q4 = select(function (x) { res = new.env(); res$empno = x$empno; res$ename = x$ename;
+              res$salary = dol_to_euro2(x$sal); res },
+     where(function (x) x$sal >= minsalary,
+     from(emp)))
+results4 = query.force(q4)
+for (r in results4) { print (sprintf("%d, %s, %d", r$empno, r$ename, r$salary)) }

com.oracle.truffle.r.test/tests/pgsql/QueryLambda.R

+emp = new.table("emp", "PostgreSQL", "postgre.config", "public")
+minsalary = 2500
+q2 = select(function (x) { res = new.env(); res$empno = x$empno; res$ename = x$ename;
+              res$salary = (function (dol) dol * 89 / 100)(x$sal); res },
+     where(function (x) x$sal >= minsalary,
+     from(emp)))
+results2 = query.force(q2)
+for (r in results2) { print (sprintf("%d, %s, %d", r$empno, r$ename, r$salary)) }

com.oracle.truffle.r.test/tests/pgsql/QuerySimple.R

+emp = new.table("emp", "PostgreSQL", "postgre.config", "public")
+q = select(function (x) { res = new.env(); res$ename = x$ename; res },
+    from(emp))
+results = query.force(q)
+for (r in results) { print (r$ename) }