config: Add gcc-4.9.0 configuration support.
4.11/rtems-lm32: Use gcc-4.9.0 and fix gdb simulator build on Windows.

The lm32 arch builds on gcc-4.9.0 so lets move to a recent build rather
than the old 4.5.? build.

Remove stdin and stdout references and the simulator io calls in gdb
so the simulator builds on Windows.