[clang] [llvm] [MC/DC][Coverage] Loosen the limit of NumConds from 6 (PR #82448)

[NAKAMURA Takumi via cfe-commits]

chapuni wrote:

@hanickadot Your comments to `llvm/CoverageMapping.cpp` are not for this PR. See #80676 .

They are my preferences.

https://github.com/llvm/llvm-project/pull/82448