Add the export-hpctoolkit snippit to hpcrun.in so that it uses the new, uniform way of finding or setting HPCTOOLKIT root directory.
Add the export-hpctoolkit snippit to hpcrun.in so that it uses the
new, uniform way of finding or setting HPCTOOLKIT root directory.

Now, both run scripts, hpcrun and hpclink, and the csprof_syms helper
script should be completely self-contained within the hpctoolkit
install tree and not require anything from externals at run time.

zcth428/hpctoolkit,zcth428/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,zcth428/hpctoolkit,zcth428/hpctoolkit111,zcth428/hpctoolkit,zcth428/hpctoolkit111,HPCToolkit/hpctoolkit,zcth428/hpctoolkit111,zcth428/hpctoolkit111,zcth428/hpctoolkit,zcth428/hpctoolkit111,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit