Merge topic 'import-elf'

115ff6a3 cmELF: Include the ELF parsing code unconditionally
5dfa3ddb cmELF: Allow building without system ELF headers
0da1540a cmELF: Fix check for TagMipsRldMapRel
e21188df cmELF: Open file explicitly in binary mode
70cdb36d Merge branch 'upstream-elf' into import-elf
7a0a37ca elf 2021-06-23 (f13da247)
18038042 cmelf: Add script to import the FreeBSD ELF headers

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !6240