Add the ability to set breakpoints on named RenderScript reductions

- Add new `lldb_private::lldb_renderscript::RSReduceBreakpointResolver`
class that can set breakpoints on kernels that are constituent
functions of named reduction groups. Also support debugging of subsets
of the the reduction group with the `-t, --function-role` flag which
takes a comma-separated list of reduction function types
outconverter,combiner,initializer,accumulator (defaults to all)

- Add 2 new helper methods to `RenderScriptRuntime`,
  1. `CreateReductionBreakpoint(name, types)`: instantiates a new
  RSReduceBreakpointResolver and inserts that resolver into the running
  process.
  2. `PlaceBreakpointOnReduction`: which is a public helper function.

- hook up the above functionality to the command-line with new
  `CommandObject*` classes that handle parsing of function roles and
  dispatch to the runtime. These are namespaced under the snappy
  `language renderscript reduction breakpoint ...` subcommand

- [incidental] Factor multiple common uses of
  `FindFirstSymbolWithNameAndType(ConstString(".rs.info")` into static
  `IsRenderScriptScriptModule(ModuleSP module)` function, and replace
  original uses.

llvm-svn: 283362