build: build with v8 gdbjit support on supported platform

[joyeecheung]

Build it with gdbjit support on supported platforms by default allows debugging JIT-compiled code in gdb when it's also enabled at run time (via --gdbjit). Simply building it in should not incur an overhead if it's not also enabled at run time.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/70473/

[joyeecheung]

FWIW I think V8 gdbjit is currently broken - I tested both the release and debug builds, and with --gdbjit-full

$ echo "throw new Error" >> throw.js
$ gdb --args out/Debug/node --gdbjit --abort-on-uncaught-exception throw.js
(gdb) run
(gdb) bt
#0  operator() (__closure=<optimized out>) at ../../deps/v8/src/base/platform/platform-posix.cc:801
#1  v8::base::OS::Abort () at ../../deps/v8/src/base/platform/platform-posix.cc:801
#2  0x0000555556ed1251 in v8::internal::Isolate::CreateMessageOrAbort (this=this@entry=0x55555eb38000, exception=..., exception@entry=..., location=location@entry=0x7fffffffd080)
    at ../../deps/v8/src/execution/isolate.cc:2151
#3  0x0000555556ed17f0 in v8::internal::Isolate::Throw (this=this@entry=0x55555eb38000, raw_exception=..., location=<optimized out>, location@entry=0x0) at ../../deps/v8/src/execution/isolate.cc:2250
#4  0x000055555789f921 in v8::internal::__RT_impl_Runtime_Throw (isolate=0x55555eb38000, args=...) at ../../deps/v8/src/runtime/runtime-internal.cc:63
#5  v8::internal::Runtime_Throw (args_length=<optimized out>, args_object=0x7fffffffd148, isolate=0x55555eb38000) at ../../deps/v8/src/runtime/runtime-internal.cc:60
#6  0x00007fffd7e16a36 in ?? ()
#7  0x00000bc71f7dd791 in ?? ()
#8  0x00007fffffffd120 in ?? ()
#9  0x0000000000000006 in ?? ()
#10 0x00007fffffffd168 in ?? ()
#11 0x00007fffd7f7c1b7 in ?? ()
#12 0x000001cd76d63641 in ?? ()
#13 0x000000000000037e in ?? ()
#14 0x00007fffffffd268 in ?? ()
#15 0x0000000000000026 in ?? ()
#16 0x00007fffffffd268 in ?? ()
#17 0x00007fffd7d51513 in ?? ()
--Type <RET> for more, q to quit, c to continue without paging--

It's also broken when I tried to test it in upstream d8, though with --gdbjit-full it could at least show trampoline frames and not show bogus frames/corrupted stack, but still it cannot symbolicate properly. Trying to force it into Turbofan didn't make any difference either.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/70488/