Update RISC-V tool chain to support standard 64-bit chips

[Sebastian Huber]

First step is to include this bug fix in Binutils:

​https://sourceware.org/bugzilla/show_bug.cgi?id=23244

Second step is a multilib update. Third step is a merge of the riscv32 and riscv64 tool chains into a single riscv tool chain.

[Sebastian Huber <sebastian.huber@…>]

In 9530518/rtems-source-builder:

Build only the Binutils

The Binutils and GDB share a repository. In order to build the Binutils
from a repository snapshot some components must be disabled.

Update #3452.

[Sebastian Huber <sebastian.huber@…>]

In f432e19/rtems-source-builder:

5: Update RISC-V Binutils

This includes the following bug fix:

​https://sourceware.org/bugzilla/show_bug.cgi?id=23244

Update #3452.

[Sebastian Huber <sebastian.huber@…>]

In 8ee4e8c/rtems-source-builder:

5: Update RISC-V Binutils and GDB

This includes the following bug fix:

​https://sourceware.org/bugzilla/show_bug.cgi?id=23305

Update #3452.

[Sebastian Huber <sebastian.huber@…>]

In 4bd8de5/rtems-source-builder:

5: Use GCC 8 snapshot for RISC-V

This picks up the new multilib set for RISC-V.

Update #3452.

[Sebastian Huber <sebastian.huber@…>]

In dc6b940/rtems-source-builder:

5: Update Newlib

Update RISC-V GCC to a GCC 9 branch commit.

Close #3342.
Close #3343.
Update #3452.

[Sebastian Huber <sebastian.huber@…>]

In d33c151/rtems-source-builder:

5: Merge riscv32 and riscv64 into riscv

After several upstream updates in Binutils, GCC, Newlib, and GDB it is
now possible to use a common riscv tool chain for the 32-bit and 64-bit
RISC-V.

Update GDB to ce73f310150418a9a1625ab60a527d959096a9e2 Git commit.

Close #3452.

[Sebastian Huber <sebastian.huber@…>]

In 2ef6dfe9/rtems-source-builder:

5: Fix rtems-all due to recent RISC-V changes

Update #3452.

[Sebastian Huber]

Another tool chain issue:

​https://sourceware.org/bugzilla/show_bug.cgi?id=23451

[Sebastian Huber <sebastian.huber@…>]

In 2cd6cef/rtems-source-builder:

5: Change riscv to riscv32

This is a temporary workaround for this bug:

​https://sourceware.org/bugzilla/show_bug.cgi?id=23451

It is not clear how this can be resolved upstream.

Update #3452.

[Sebastian Huber <sebastian.huber@…>]

In c40d126/rtems-source-builder:

5: Change riscv32 back to riscv

Update Binutils to include a bug fix for:

​https://sourceware.org/bugzilla/show_bug.cgi?id=23451

Update #3452.

[Sebastian Huber <sebastian.huber@…>]

In 8f74240/rtems-source-builder:

5: Update Newlib

It includes a fix for bug in the ctype support, some FreeBSD
compatibility changes in <sys/cdefs.h> for libbsd and a new
configuration option for all targets newlib/configure.host which is used
by the RISC-V port.

Close #3452.

[Sebastian Huber <sebastian.huber@…>]

In 79c83cd/rtems-source-builder:

5: Update Newlib for RISC-V

Use the latest Newlib to fix the GCC libgomp build (TLS support was not
detected due to broken crt0).

Update #3452.