Improving the performance of breakpoints up to 50% (by playing with laziness)

Improving the performance of breakpoints up to 50% (by playing with laziness)

This patch performs several optimizations with the goal of minimizing the cost of building the arguments to breakpointJump:
  - Group them all in a single tuple, to minimize closure creation in heap
  - Wrap this with the GHC.Base.lazy combinator, to induce max laziness
  - Remove as many literal strings as possible
    * injecting a module-local CAF to store the module name and use that
    * eliminating the package string (not needed).