package/gcc/9.1.0: fix ICE on ARC

package/gcc/9.1.0: fix ICE on ARC

In a nutshell while compiling glibc GCC raises an Internal Compiler
Error (ICE).

This is a backport of upstream fix [1] for GCC's BUG #89838 [2].
The fix is the same as the one already merged for arc-2019.03 [3].

With the update of GCC to 9.2.0, this patch won't be needed anymore:
it's already merged in both the stable "gcc-9-branch" branch and the
"master" branch.

[1] https://github.com/gcc-mirror/gcc/commit/472bac30e63ffacecfa5eda813054555f2cc7def
[2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89838
[3] https://git.buildroot.org/buildroot/commit/?h=dbf7fffb37e25c40fd5c03d0a64e50a1bba86424

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Evgeniy Didin <didin@synopsys.com>
Cc: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>