Low: gcc security update (Oracle Linux 8)

gcc [el8]
[8.5.0-18.0.5]
- CVE-2023-4039 GCC mitigation.
Orabug 35751743.
Includes removal of aarch64-preserve-args.patch.
- CVE-2022-40982 'Intel Downfall' mitigation.
Orabug 35751810.
Add two patches originally from GCC upstream releases/gcc-11 branch.
with major adjustment.
gcc11-downfall-disable-gather-in-vec.patch
gcc11-downfall-support-mno-gather.patch
Reviewed-by: Jose E. Marchesi <jose.marchesi@oracle.com>

gcc [el9]
[11.3.1-4.3.0.4]
- CVE-2023-4039 GCC mitigation.
Orabug 35751837.
- CVE-2022-40982 'Intel Downfall' mitigation.
Orabug 35751842.
Add two patches originally from GCC upstream releases/gcc-11 branch.
gcc11-downfall-disable-gather-in-vec.patch
gcc11-downfall-support-mno-gather.patch
Reviewed-by: Jose E. Marchesi <jose.marchesi@oracle.com>

gcc-toolset-11-gcc [el8]
[11.2.1-9.1.0.6]
- CVE-2023-4039 GCC mitigation.
Orabug 35751885.
- CVE-2022-40982 'Intel Downfall' mitigation.
Orabug 35751901.
Add two patches originally from GCC upstream releases/gcc-11 branch.
gcc11-downfall-disable-gather-in-vec.patch
gcc11-downfall-support-mno-gather.patch
Reviewed-by: Jose E. Marchesi <jose.marchesi@oracle.com>

gcc-toolset-12-gcc [el8/el9]
[12.2.1-7.4.0.2]
- CVE-2023-4039 GCC mitigation.
Orabug 35751931.
- CVE-2022-40982 'Intel Downfall' mitigation.
Orabug 35751938.
Add two patches originally from GCC upstream releases/gcc-11 branch.
gcc12-downfall-disable-gather-in-vec.patch
gcc12-downfall-support-mno-gather.patch
- Introduce 'oracle_release' into .spec file. Echo it to gcc/DEV-PHASE.