Fix issue 19128 - argument to alloca may be too large

[ibuclaw]

Replaces #2258.

[dlang-bot]

Thanks for your pull request, @ibuclaw!

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	19128	enhancement	argument to alloca may be too large

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub fetch digger
dub run digger -- build "master + druntime#2409"

[ibuclaw]

Dammit windows, doesn't support basic functionality.

Error: cannot mix `core.std.stdlib.alloca()` and exception handling in `_d_arrayassign()`
--- errorlevel 1

[ibuclaw]

Only fixed _d_arraysetassign to not use scope(exit).

For _d_arrayassign partially reverted back to use void[16] if the element fits, otherwise always use malloc(). This is fine IMO, as this function is deprecated, and the compiler should be calling _d_arrayassign_l directly itself.

[PetarKirov]

Suggested change

	// Need a temporary buffer tmp[] big enough to hold one element
	// Need a temporary buffer big enough to hold one element.
	// Stack allocate if element_size < 512.

[PetarKirov]

I wonder if it makes sense to abstract the repeated code via mixins. Otherwise LGTM, modulo nits on the comments.

[thewilsonator]

Please give the a kick, FreeBSD seems to be getting a lot of those socket errors.

[wilzbach]

Please give the a kick, FreeBSD seems to be getting a lot of those socket errors.

Auto-tester's agents will automatically restart.

[wilzbach]

Though I merged this manually as currently some Buildkite agents are running into timeouts.