New RenderScript command to break on all kernels

Patch adds a command to RenderScript plugin allowing users to automatically set breakpoints on every RS kernel.

Command syntax is 'language renderscript kernel breakpoint all <enable/disable>.'
Enable sets breakpoints on all currently loaded kernels, and any kernels which will be loaded in future.
Disable results in breakpoints no longer being set on loaded kernels, but doesn't affect existing breakpoints.

Current command 'language renderscript kernel breakpoint' is changed to 'language renderscript kernel breakpoint set'

Reviewed by: clayborg, jingham
Subscribers: lldb-commits, ADodds, domipheus
Differential Revision: http://reviews.llvm.org/D12728

llvm-svn: 247262