[crosstool-ng/crosstool-ng] de76f7: ARC: Support building of multi-lib Glibc toolchain

[Alexey Neyman]

  Branch: refs/heads/master
  Home:   https://github.com/crosstool-ng/crosstool-ng
  Commit: de76f7cc82eedac5653283a99c1c7083d7a0d43b
      https://github.com/crosstool-ng/crosstool-ng/commit/de76f7cc82eedac5653283a99c1c7083d7a0d43b
  Author: Alexey Brodkin <abrodkin@synopsys.com>
  Date:   2019-06-14 (Fri, 14 Jun 2019)

  Changed paths:
    A samples/arc-multilib-linux-gnu/crosstool.config
    A samples/arc-multilib-linux-gnu/reported.by
    M scripts/build/arch/arc.sh

  Log Message:
  -----------
  ARC: Support building of multi-lib Glibc toolchain

>From GCC's standpoint ARC's multilib items are defined by "mcpu" values
which we have quite a few and for all of them might be built optimized
cross-toolchain.

>From Glibc's standpoint multilib is just multi-ABI [1] and so very limited
versions are supposed to co-exist (e.g. arc700 & archs).

Here we force Glibc to install libraries in GCC's multilib folder to create
a universal cross-toolchain that has libs optimized for multiple CPU types.

But note we only need to mess with installation paths in case of real
multilib, otherwise we keep default "lib/" paths so that GCC finds default
(the one and only) libs where it expects them to be.

Also here we add a sample which allows to build universal Glibc Linux
toolchain for ARC.

[1] https://sourceware.org/ml/libc-alpha/2019-06/msg00018.html

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>


  Commit: be5d0317d23ce7d3c4eb497d21ec7c27b0acf6de
      https://github.com/crosstool-ng/crosstool-ng/commit/be5d0317d23ce7d3c4eb497d21ec7c27b0acf6de
  Author: Alexey Neyman <stilor@att.net>
  Date:   2019-12-23 (Mon, 23 Dec 2019)

  Changed paths:
    A samples/arc-multilib-linux-gnu/crosstool.config
    A samples/arc-multilib-linux-gnu/reported.by
    M scripts/build/arch/arc.sh

  Log Message:
  -----------
  Merge pull request #1201 from abrodkin/topic-glibc-multilib

ARC: Support building of multi-lib Glibc toolchain


Compare: https://github.com/crosstool-ng/crosstool-ng/compare/e0a63b854608...be5d0317d23c