update callgrind and cachegrind filtering logic following rev 14469
rev 14469 gives better description of the tweak done to the
simulated cache. Update filtering logic to filter this (variable) tweaking
msg.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14486 a5019735-40e9-0310-863c-91ae7b9d1cf9
Go back to $test_dirs after each test run or tests dir run
Otherwise, we get an error for the 2nd dir if specifying 2 directories e.g.

  perl tests/vg_regtest cachegrind/tests callgrind/tests
  -- Running  tests in cachegrind/tests ----------------------------------
  chdir:           valgrind   ./chdir 
  clreq:           valgrind   -q ./clreq 
  dlclose:         valgrind   ./dlclose 
  notpower2:       valgrind   --I1=32768,8,64 --D1=24576,6,64 --LL=3145728,12,64 ./../../tests/true 
  wrap5:           valgrind   ./../../memcheck/tests/wrap5 
  -- Running  tests in cachegrind/tests/x86 ------------------------------
  fpu-28-108:      valgrind   ./fpu-28-108 
  -- Finished tests in cachegrind/tests/x86 ------------------------------
  -- Finished tests in cachegrind/tests ----------------------------------
  `callgrind/tests' neither a directory nor a readable test file/name



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14487 a5019735-40e9-0310-863c-91ae7b9d1cf9