fix sdl_test test that failed in CI cpp mode

[timotheecour]

note

the fixed code now matches the declaration of drawLines which expects cint, not int32

proc drawLines*(renderer: SdlRendererPtr, points: ptr tuple[x, y: cint],
    count: cint): cint {.importc: "SDL_RenderDrawLines", discardable.}

note that cint isnt' defined by type cint = int32 but as follows:

type cint* {.importc: "int", nodecl.} = int32

note

after #10313 and #10310 there will be 1 last failing tests before we can enable nim cpp in CI:

• tests/objects/tobjcov.nim

[Araq]

That's not good, the point of these tests is that they continue to work. I think instead we should compile "Nim in Action" examples always in C mode.

[timotheecour]

but cpp is intended to be future default IIRC. i'll instead use when defined(cpp) block and use old impl for c

[Araq]

These example programs should only be touched if absolutely necessary.

[timotheecour]

PTAL

That's not good, the point of these tests is that they continue to work

disabling cpp mode because they fail in nim cpp mode goes in the opposite direction of making sure these tests continue to work.
I just pushed a commit that'll run these tests exactly the way they did in NimInAction book when in C mode, while still making sure that example stays supported in cpp mode so a user inspired to port/adapt that example to nim cpp will have an easier time.

[Araq]

Not what I had in mind, but alright.