Maintenance and merging of Valgrind and Valgrind-Freya code paths (#2362)

None of the code paths have been tested for long and especially the
Freya code paths have been long abandoned. This patch:
- Merges Valgrind-Freya into Valgrind code path (there should be no
  need to choose between them, Valgrind should work just fine).
- Removes leftover code (`VALGRIND_FREYA_CHECK_MEMPOOL_REQUEST` and
  `valgrind_freya_mempool_request`).
- Adds `JMEM_` prefix to Valgrind-related macros (to correctly
  leave the `VALGRIND_` prefix to Valgrind).
- Moves the definition of the Valgrind-related macros to a common
  header to avoid duplication.

Note: Adding a CI job to perform Valgrind Memchecks is left for
follow-up as it turns out to be excessively slow (>50 mins for a
`--jerry-tests --jerry-test-suite` run, and even a simple
`--jerry-tests` may get terminated prematurely because of timeout
issues).

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

tools/build.py

@@ -136,8 +136,6 @@ def get_arguments():
                           help=devhelp('enable regexp byte-code dumps (%(choices)s; default: %(default)s)'))
     devgroup.add_argument('--valgrind', metavar='X', choices=['ON', 'OFF'], default='OFF', type=str.upper,
                           help=devhelp('enable Valgrind support (%(choices)s; default: %(default)s)'))
-    devgroup.add_argument('--valgrind-freya', metavar='X', choices=['ON', 'OFF'], default='OFF', type=str.upper,
-                          help=devhelp('enable Valgrind-Freya support (%(choices)s; default: %(default)s)'))
 
     arguments = parser.parse_args(args)
     if arguments.devhelp:
@@ -193,7 +191,6 @@ def generate_build_options(arguments):
     build_options.append('-DFEATURE_REGEXP_STRICT_MODE=%s' % arguments.regexp_strict_mode)
     build_options.append('-DFEATURE_REGEXP_DUMP=%s' % arguments.show_regexp_opcodes)
     build_options.append('-DFEATURE_VALGRIND=%s' % arguments.valgrind)
-    build_options.append('-DFEATURE_VALGRIND_FREYA=%s' % arguments.valgrind_freya)
 
     build_options.extend(arguments.cmake_param)