RenderScript command for printing allocation contents

This patch adds the command 'language renderscript allocation dump <ID>' for printing the contents of a RS allocation.
Displaying the coordinate of each element as well as its formatted value

e.g (lldb) language renderscript allocation dump 1
      Data (X, Y, Z):
     (0, 0, 0) = {0 1}
     (1, 0, 0) = {2 3}
     (2, 0, 0) = {4 5}

A --file <filename> option is also included, since for large allocations it may be more helpful to view this text as a file.

Reviewed by: jingham, clayborg
Subscribers: lldb-commits, ADodds, domipheus, brucem
Differential Revision: http://reviews.llvm.org/D13699

llvm-svn: 250281