Add better support for proper installation after build (#2370)

- Add `--install` option to `tools/build.py`.
- Make use of `--install` in `tools/run-tests.py` by testing the
  installed the executables instead of those in the build tree.

Related changes:
- Collect unit test binaries in the `tests` subdir of the build
  tree instead of `bin`.
- The `ls`-based collection of the unit test binaries had some
  shortcomings hitherto unrevealed (it didn't filter for files so
  it could potentially "collect" dictionaries, too), which has now
  been replaced with a more stable `find`-based solution.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

tools/runners/run-unittests.sh

@@ -29,8 +29,8 @@ UNITTEST_OK=$DIR/unittests.passed
 
 rm -f $UNITTEST_ERROR $UNITTEST_OK
 
-UNITTESTS=$(ls $DIR/unit-*)
-total=$(ls $DIR/unit-* | wc -l)
+UNITTESTS=$(find $DIR -maxdepth 1 -type f -name 'unit-*')
+total=$(find $DIR -maxdepth 1 -type f -name 'unit-*' | wc -l)
 
 if [ "$total" -eq 0 ]
 then