[lld] [llvm] [LLD][COFF] Add more `--time-trace` tags for ThinLTO linking (PR #156471)

[Teresa Johnson via llvm-commits]

================
@@ -1550,6 +1551,7 @@ void llvm::computeDeadSymbolsWithConstProp(
     const DenseSet<GlobalValue::GUID> &GUIDPreservedSymbols,
     function_ref<PrevailingType(GlobalValue::GUID)> isPrevailing,
     bool ImportEnabled) {
+  llvm::TimeTraceScope timeScope("Dead symbols");
----------------
teresajohnson wrote:

Maybe "Drop dead symbols and propagate attributes"? It might be good to have timers on each of the below functions as well, to distinguish their times.

https://github.com/llvm/llvm-project/pull/156471