[llvm] [llvm][DebugInfo] Require non-null debug metadata fields when writing bitcode (PR #198441)

[Jiang Ning via llvm-commits]

JiangNingHX wrote:

@Michael137 Hi,  I’m happy to either keep the broader scope here or split this down to just DISubprogram::type if you’d prefer. Let me know which direction you’d like, and I’ll adjust accordingly.

https://github.com/llvm/llvm-project/pull/198441