test: run v8 tests

Ported by exinfinitum from a PR by jasnell: see https://github.com/nodejs/node-v0.x-archive/pull/14185

Allows the running of v8 tests on node's packaged v8 source code.

Note that the limited win32 support added by jasnell has NOT been ported, and so these tests are currently UNIX ONLY.

Note that gclient depot tools (see https://commondatastorage.googleapis.com/ chrome-infra-docs/flat/depot_tools/docs/html/ depot_tools_tutorial.html#_setting_up) and subversion are required to run tests.

To perform tests, run the following commands:

make v8 DESTCPU=(ARCH) make test-v8 DESTCPU=(ARCH)

where (ARCH) is your CPU architecture, e.g. x64, ia32. DESTCPU MUST be specified for this to work properly.

Can also do tests on debug build by using "make test-v8 DESTCPU=(ARCH) BUILDTYPE=Debug", or perform intl or benchmark tests via make test-v8-intl or test-v8-benchmarks respectively.

Note that by default, quickcheck and TAP output are disabled, and i18n is enabled. To activate these options, use options"QUICKCHECK=True" and "ENABLE_V8_TAP=True" respectively. Use "DISABLE_V8_I18N" to disable i18n.

Any tests performed after changes to the packaged v8 file will require recompiling of v8, which can be done using "make v8 DESTCPU=(ARCH)".

Finally, several additional files necessary for one of the v8 tests have been added to the v8 folder.