don't introduce 'dispose', use '=dispose', fixes #17003 [backport:1.4]

[Araq]

No description provided.

[timotheecour]

• what about these:

compiler/liftdestructors.nim:744:48:  #var disposeCall = genBuiltin(c.g, mDispose, "dispose", x)
doc/destructors.rst:626:6:      dispose(x)
lib/pure/asyncdispatch.nim:370:15:        system.dispose(customOverlapped.data.cell)
lib/pure/asyncdispatch.nim:381:17:          system.dispose(customOverlapped.data.cell)
lib/system/arc.nim:167:6:#proc dispose*(x: pointer) = nimRawDispose(x)
lib/system/gc_common.nim:96:5:proc dispose*(x: ForeignCell) =
lib/system/mmdisp.nim:110:7:  proc dispose*(x: ForeignCell) = discard
lib/system/orc.nim:102:30:      cstderr.rawWrite "lacks dispose"
lib/system/orc.nim:108:28:      cstderr.rawWrite "has dispose!\n"

(some of which are just in comments/msgs but still)

• I think there should be a "type bound routine" section in manual mentioning that routines (not operators) starting with = (eg: =destroy) are type bound, ie (in my understanding) are attached to a type, regardless of whether they're in import scope.

  AttachedOpToStr*: array[TTypeAttachedOp, string] = [
    "=destroy", "=copy", "=sink", "=trace", "=dispose", "=deepcopy"]

there is already https://nim-lang.github.io/Nim/destructors.html#lifetimeminustracking-hooks but it's incomplete, and less searcheable / not very clear.

(see also proposed =default in nim-lang/RFCs#290)

EDIT: for the 2nd point => #17063