Change the LLVM signpost category

[JDevlieghere]

Summary

Currently, the LLVM timers are visible in Instruments for all apps. The Developer-visible "PointsOfInterest" category, is reserved for Runtime Issues and Developer-authored "important" logging. These are visible to developer almost always in Instruments, and having these present in the system is noisy and confusing to developers. The LLVM/LLDB timers do not belong there. Change them to a new "toolchain" category.

rdar://91266582

[dsanders]

LGTM

llvm/lib/Support/Signposts.cpp

 using namespace llvm;
 
 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
 #define SIGNPOSTS_AVAILABLE()                                                  \
   __builtin_available(macos 10.14, iOS 12, tvOS 12, watchOS 5, *)
 namespace {
 os_log_t *LogCreator() {
   os_log_t *X = new os_log_t;
-  *X = os_log_create("org.llvm.signposts", OS_LOG_CATEGORY_POINTS_OF_INTEREST);
+  *X = os_log_create("org.llvm.signposts", "toolchain");
   return X;
 }
 struct LogDeleter {
   void operator()(os_log_t *X) const {
     os_release(*X);
     delete X;
   }
 };