[compiler-rt] [llvm] [ctxprof] Make ContextRoot an implementation detail (PR #131416)

[Snehasish Kumar via llvm-commits]

================
@@ -336,10 +336,28 @@ void setupContext(ContextRoot *Root, GUID Guid, uint32_t NumCounters,
   AllContextRoots.PushBack(Root);
 }
 
+ContextRoot *FunctionData::getOrAllocateContextRoot() {
+  auto *Root = CtxRoot;
+  if (!Root) {
----------------
snehasish wrote:

How about 
```
if(CtxRoot) return CtxRoot;
__sanitizer::GenericScopedLock<__sanitizer::StaticSpinMutex> L(&Mutex);
auto *Root = CtxRoot;
...
```

to reduce 1 level of nesting?


https://github.com/llvm/llvm-project/pull/131416