gcc: Fixes for ARC

A couple of fixes to be a part of 11.2 whenever it happens

1. https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=0061fabeb9393c362601486105202cfe837a5a68
   Fixes "harfbuzz" build, see https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/issues/382
   for all the gory details.

2. https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=4186b7e93be73f8d68dc0fcc00a4cc8cc83e99a8
   Fixes ext4 run-time issue:
   ------------------------->8---------------------------
   Path: /bin/busybox
   CPU: 0 PID: 1 Comm: init Not tainted 5.13.0-rc2-dirty #23
   Invalid Read @ 0x41c9e600 by insn @ __bio_try_merge_page+0x4e/0xfc
   ECR: 0x00050100 EFA: 0x41c9e600 ERET: 0x80159656
   STAT: 0x80080202 [IE K     ]   BTA: 0x80159648
    SP: 0x80821b88  FP: 0x00000008 BLK: bio_add_page+0x22/0x5c
   LPS: 0x801a6a94 LPE: 0x801a6a98 LPC: 0x00000000
   r00: 0x80823300 r01: 0xbfb85e38 r02: 0x00002000
   r03: 0x00000000 r04: 0x80821b9b r05: 0x80821bfc
   r06: 0x00000000 r07: 0x00000700 r08: 0x00000000
   r09: 0xffffffff r10: 0x00000000 r11: 0x00000000
   r12: 0x8080b300
   Stack Trace:
     __bio_try_merge_page+0x4e/0xfc
     bio_add_page+0x22/0x5c
     do_mpage_readpage+0x534/0x65c
     mpage_readahead+0x30/0xdc
     read_pages+0x34/0x194
     page_cache_ra_unbounded+0x56/0x154
     filemap_fault+0x25a/0x5d8
     __do_fault+0x94/0xe8
     handle_mm_fault+0x4de/0xbd4
     do_page_fault+0x108/0x21c
     ret_from_exception+0x0/0x8
   ------------------------->8---------------------------

3. https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=5a9b6a004f89fdd95b0470e1324dc4dee8c41d24


   Precautious fix for rare corner cases which we don't wnat to really end-up in.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>