Fixed EGPR SIB.base handling #1003

Job	Run time
CMake build + tests (macos-latest )	13s
MSBuild build (windows-2022)	1m 2s
CMake build + tests (macos-latest -DZYAN_NO_LIBC=ON)	11s
fuzzing (address)	1m 29s
CMake build + tests (windows-2022 )	56s
Meson build + tests (macos-latest, debug default)	19s
fuzzing (undefined)	1m 32s
CMake build + tests (windows-2022 -DZYAN_NO_LIBC=ON)	29s
Meson build + tests (windows-2022, debug default)	1m 27s
fuzzing (memory)	1m 31s
Amalgamated build (Ubuntu 22.04)	9s
CMake build + tests (ubuntu-22.04 )	8s
Meson build + tests (ubuntu-22.04, debug default)	20s
CMake build + tests (ubuntu-22.04 -DZYAN_NO_LIBC=ON)	18s
Meson build + tests (windows-2022, debug NO_LIBC)	1m 51s
CMake build + tests (ubuntu-22.04 -DZYDIS_MINIMAL_MODE=ON -DZYDIS_FEATURE_ENCODER=OFF)	8s
Meson build + tests (ubuntu-22.04, debug NO_LIBC)	9s
CMake build + tests (windows-2022 -TClangCL)	1m 24s
Meson build + tests (macos-latest, release default)	20s
Meson build + tests (windows-2022, release default)	1m 58s
Meson build + tests (ubuntu-22.04, release default)	20s
Meson build + tests (windows-2022, release NO_LIBC)	1m 43s
Meson build + tests (ubuntu-22.04, release NO_LIBC)	13s
Meson build + tests (ubuntu-22.04, minsize )	21s
	18m 31s

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