ci : add an option to fail on compile warning (llama/3952)

ci : add an option to fail on compile warning (llama/3952)

* feat(ci): add an option to fail on compile warning

* Update CMakeLists.txt

* minor : fix compile warnings

ggml-ci

* ggml : fix unreachable code warnings

ggml-ci

* ci : disable fatal warnings for windows, ios and tvos

* ggml : fix strncpy warning

* ci : disable fatal warnings for MPI build

* ci : add fatal warnings to ggml-ci

ggml-ci

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Co-authored-by: Georgi Gerganov <redacted>