[dmd-cxx] Backport a number of bindings and fixes from master

[ibuclaw]

Bindings are HPPA support, and some work towards OSX.

Backport of core.internal.hash is a primer for another PR that will fix hashing of complex reals.

[dlang-bot]

Thanks for your pull request, @ibuclaw!

Bugzilla references

Your PR doesn't reference any Bugzilla issue.

If your PR contains non-trivial changes, please reference a Bugzilla issue or create a manual changelog.

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 "dmd-cxx + druntime#2469"

[PetarKirov]

@ibuclaw the only commit that I have doubts for is 0cbe48d. What was your process in making it, as I guess it encompasses tens of commits from the master branch.

[ibuclaw]

@ZombineDev - meld mostly.

The ultimate patch is it intended for is #2356 fix to apply cleanly and work.

The original patch sent to me on gcc mailing list had the minimum required backported in order to use it in core.internal.hash, I suggested that instead all PRs leading up to should be backported in order to simplify transition from dmd-cxx to master (the minimum changes were already non-trivial anyway).

Pretty much its all the work of @n8sh squashed into one. There are only a couple omissions that depended on newer compiler features. Nothing that was a regression anyway.

To give a small list of PRs I looked at (just copied from my mail response):

2197, 2202, 2210, 2200, 2227, 2209,
2198, 2243, 2240, 2246, 2311

There are many more, and I'm not going to apply them individually. :-)

[PetarKirov]

Alright, thanks for the info!