Print relative real paths when running tests.

For example, on my setup, this changes:

    ./tools/test.py --fast
    [...]
    /work/vixl/vixl/obj/mode_debug/symbols_on/CXX_clang++/std_c++98/simulator_on/benchmarks/aarch64/bench-branch-link-masm
    [...]

to

    ./tools/test.py --fast
    [...]
    obj/mode_debug/symbols_on/CXX_clang++/std_c++98/simulator_on/benchmarks/aarch64/bench-branch-link-masm
    [...]


Change-Id: I369e49fe0ef65d4ce313a0bfb8e3ed99bf4dbd61
diff --git a/tools/test.py b/tools/test.py
index 34c8983..7a08ac1 100755
--- a/tools/test.py
+++ b/tools/test.py
@@ -344,7 +344,7 @@
   benchmark_names = util.ListCCFilesWithoutExt(config.dir_aarch64_benchmarks)
   for bench in benchmark_names:
     rc |= RunCommand(
-      [os.path.realpath(
+      [util.relrealpath(
           join(config.dir_build_latest, 'benchmarks/aarch64', bench))])
   return rc
 
@@ -417,7 +417,7 @@
 
       # Use the realpath of the test executable so that the commands printed
       # can be copy-pasted and run.
-      test_executable = os.path.realpath(
+      test_executable = util.relrealpath(
         join(config.dir_build_latest, 'test', 'test-runner'))
 
       if not args.notest: