BRIGFE fixes:

BRIGFE fixes:

* brig-builtins.def: Treat HSAIL barrier builtins as
  setjmp/longjump style functions.

* brigfrontend/brig-to-generic.cc: Ensure per WI copies of
  private variables are aligned too.

* rt/workitems.c: Assume the host runtime allocates the work group
  memory.

From-SVN: r253160