[2pt] Report all JIT-related allocations as internal

Product: Tarantool
Since: 2.10
Root document: https://www.tarantool.io/en/doc/latest/book/app_server/luajit_memprof/
Dev issue: https://github.com/tarantool/tarantool/issues/5679
SME: @ igormunkin , @ Buristan

Details

The memory profiler reports the source line as 0 if a trace or other JIT-related stuff is allocated inside some Lua chunk.

For example, if we have the <test.lua> file with the following code

local f1, msg1, errno1 = misc.memprof.start("/tmp/tmp_memprofile.bin")
for _ = 1, 100 do
  local _ = {_, _}
end

we get the following output from the profiler parser.

ALLOCATIONS
@test.lua:0, line 3: 57    3192    0
@test.lua:0, line 0: 4     640     0 <- JIT-related allocations
INTERNAL: 2     438     0

REALLOCATIONS

DEALLOCATIONS
INTERNAL: 24    0       1177
        Overrides:
                @test.lua:0, line 3
                INTERNAL

It can confuse the users, so it's better to report all JIT-related allocations as INTERNAL.

Start with the root document on LuaJIT memory profiling and the linked development issue 5679, then reproduce the example using misc.memprof.start and inspect the reported output. Done means every trace or other JIT-related allocation is reported as INTERNAL rather than with a source line of 0.