Since QEMU is far from stable, I'm tagging a version of QEMU in here
that's compatible with the current ABI.  This may change in the future.

Add support for --with-guile configure flag

Bump newlib to 2.5

And re-run autoreconf to generate the configure script.

Signed-off-by: Johannes Löthberg <johannes@kyriasis.com>

16210e6 RISC-V: Handle non-legitimate address in riscv_legitimize_move

This makes it easier to use this repo to build other toolchains,
as I occasionally want to do.

I'm hoping this will speed up our builds a bit, as we'll no longer be
executing in a VM but instead in a container.

ff03ebe RISC-V: Add Sign/Zero extend patterns for PIC loads
2fe94d5 RISC-V: Add -mstrict-align option
f9771ad RISC-V: Unify indention in riscv.md

RISC-V: Fix disassemble for c.li, c.andi and c.addiw

Update binutils and glibc

 * RISC-V: Prohibit relaxing the initial gp generation

 * RISC-V: Change CALL macro to use ra as the temporary address register
 * RISC-V: Allow 32-bit BFD to handle 64-bit objects
 * RISC-V: Resurrect GP-relative disassembly hints
 * RISC-V/bfd: Hook elf_backend_object_p to set the mach type.

Allow users to flip "--with-system-zlib"

We need this to have different polarity for different platforms (Windows
vs RedHat).  I don't know how to autodetect this for now, so I'm just
doing it manually.

This reverts commit 237c8816.

Allow Windows builds

This doesn't work on all our target platforms (Windows, for example).

Use the GCC 7.1 release

I need to set this in order to build the Windows tools.

Fix --with-headers= path for newlib toolchain

 - Wrong --with-headers= path will cause libgcov build incorrectly.

Let users specify the "-mcmodel" argument to libc/libgcc

This lets users select the code model when building the tools.

This lets users pass extra CFLAGS to the embedded library builds, which
lets us do things like target the medany code model.

Move GCC to the 7 release branch

GCC has created a stable branch upstream for the 7 release series.  This
patch moves our GCC sources over to that branch, just like we did for
binutils.

gdb-sim accounted for nearly all test failures, so don't use it for now.

For some reason, a Newlib multilib build includes a "default" library
in addition to the multilibs ones.  This results in confounding error
messages when an invalid multilib is requested on the GCC command line.
Now, it reports a more sensible "cannot find -lc".