Update config scripts to compile for Apple Silicon (arm64)

[markpeek]

Detect Apple Silicon (arm64) during configuration for compilation on macOS 11.0 (beta at this time). Fixes ERL-1305.

Main changes:

• Fix the integer macOS version correctly for the build version check
• Map correctly to 64bit builds (-m64)

Verified via ./otp_build tests

Note: the current config.guess uses "arm-apple-darwin*" for the build/host system type while a newer version uses "aarch64-apple-darwin*". However, the diffs between 2015-03-04 to 2020-07-12 were outside the scope of being able to test for this PR.

[CLAassistant]

All committers have signed the CLA.

[markpeek]

@rickard-green PR updated per your review.

[rickard-green]

Please rebase this onto the maint branch, so we can release it in next maintenance patch (OTP 23.1). Now it is based on master which is for the next release (OTP 24).

[rickard-green]

I've rebased this to maint and merged it

[michaelklishin]

Any chance this can get into maint-22 and such for us poor souls on Big Sur who have to occasionally test on Erlang 22.3?

[amarBitMan]

@rickard-green
Can we get the fix for erlang 20.3 also?

[rickard-green]

@amar1994 Sorry, no OTP 20 is not maintained anymore

[amarBitMan]

@rickard-green:
Is there any workaround for this (I mean getting the fix on a custom version of OTP-20)?

[rickard-green]

You want to cherry-pick the following commits onto the base commit of your choice (the once marked "test" only affect test-cases):

• 2b91ffd (test)
• 3284a80 (test)
• f1ba748 (test)
• f32b878
• fd86ab1
• 43f33b4
• daaf5e3
• 2c37b50

Hopefully they should be possible to cherry-pick to a late OTP 20 without conflicts, but that is not guaranteed.

[amarBitMan]

@rickard-green
I cherry-picked the above commits on top of the maint-20 branch. But when I tried to build and install it using kerl, it was installed as erlang 24.
When I type erl after activating it, getting following output ->

➜  otp git:(maint-20) erl
Erlang/OTP 24 [RELEASE CANDIDATE 3] [erts-11.2] [source-dae6cd7fad] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1]

Eshell V11.2  (abort with ^G)
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