fix warnings and enable passing tests

...ibrary/src/com/oracle/truffle/r/library/stats/Cauchy.java

...r.library/src/com/oracle/truffle/r/library/stats/Exp.java

...rc/com/oracle/truffle/r/library/stats/GammaFunctions.java

...ibrary/src/com/oracle/truffle/r/library/stats/QHyper.java

...library/src/com/oracle/truffle/r/library/stats/RBeta.java

...ibrary/src/com/oracle/truffle/r/library/stats/RHyper.java

...library/src/com/oracle/truffle/r/library/stats/RMath.java

...ary/src/com/oracle/truffle/r/library/stats/RMultinom.java

...ary/src/com/oracle/truffle/r/library/stats/RNbinomMu.java

...library/src/com/oracle/truffle/r/library/stats/RPois.java

...acle/truffle/r/library/stats/RandGenerationFunctions.java

...rary/src/com/oracle/truffle/r/library/stats/Signrank.java

...ibrary/src/com/oracle/truffle/r/library/stats/Wilcox.java

...tin/src/com/oracle/truffle/r/nodes/builtin/base/Attr.java

.../src/com/oracle/truffle/r/nodes/builtin/base/Combine.java

...tin/src/com/oracle/truffle/r/nodes/builtin/base/Drop.java

.../src/com/oracle/truffle/r/nodes/builtin/base/Sprintf.java

.../com/oracle/truffle/r/nodes/builtin/base/UpdateClass.java

...fle/r/nodes/access/vector/PositionCheckSubscriptNode.java

...com/oracle/truffle/r/test/builtins/TestBuiltin_array.java