[llvm] [llvm-cov] Use JSON streaming instead of in-memory DOM (PR #192457)

[Alan Phipps via llvm-commits]

evodius96 wrote:

> @evodius96 Hi! Could you please review this PR. `llvm-cov export` output format stays the same (except for ordering as mentioned above), only json serialization is changed from constructing json objects to streaming them directly.

Thanks! I will review this next week. Thanks

https://github.com/llvm/llvm-project/pull/192457