[analyzer] Analyzer should emit IssueHash in SARIF output

[dbartol]

The SARIF format allows a result to have an optional set of partialFingerprints - opaque strings that are intended to uniquely identify the warning across runs, even when source code changes. The Clang static analyzer already computes such a fingerprint, but currently only emits it for Plist output. The SARIF emitter should do the same.

[llvmbot]

@llvm/issue-subscribers-clang-static-analyzer

Author: Dave Bartolomeo (dbartol)

The SARIF format allows a result to have an optional set of `partialFingerprint`s - opaque strings that are intended to uniquely identify the warning across runs, even when source code changes. The Clang static analyzer already computes such a fingerprint, but currently only emits it for Plist output. The SARIF emitter should do the same.

[steakhal]

Makes sense to me.