[GR-11025] Code clean-up and check ECJ warnings in CI.

ci_common/common.hocon

...ngine/src/com/oracle/truffle/r/engine/EngineRootNode.java

...ngine/src/com/oracle/truffle/r/engine/interop/ListMR.java

...ruffle/r/engine/interop/RAbstractVectorAccessFactory.java

...racle/truffle/r/engine/interop/RArgsValuesAndNamesMR.java

...c/com/oracle/truffle/r/engine/interop/REnvironmentMR.java

.../src/com/oracle/truffle/r/engine/interop/RFunctionMR.java

...e/src/com/oracle/truffle/r/engine/interop/RLogicalMR.java

.../src/com/oracle/truffle/r/engine/interop/RS4ObjectMR.java

.../com/oracle/truffle/r/ffi/impl/llvm/TruffleLLVM_Call.java

...racle/truffle/r/ffi/impl/nodes/AttributesAccessNodes.java

.../com/oracle/truffle/r/ffi/impl/nodes/ListAccessNodes.java

...src/com/oracle/truffle/r/ffi/impl/nodes/Str2TypeNode.java

...c/com/oracle/truffle/r/library/fastrGrid/GridContext.java

.../oracle/truffle/r/library/fastrGrid/device/GridColor.java

...m/oracle/truffle/r/library/stats/StatsFunctionsNodes.java

...rc/com/oracle/truffle/r/nodes/builtin/base/AsInteger.java

...oracle/truffle/r/nodes/builtin/base/BitwiseFunctions.java

.../oracle/truffle/r/nodes/builtin/base/CrossprodCommon.java

...m/oracle/truffle/r/nodes/builtin/base/FrameFunctions.java