[compiler-rt][hwasan][fuchsia] Implement InitializeOsSupport

This is empty for now, but we will add a check that TBI is enabled once the
tagged pointer ABI for zircon is finalized. This depends on D105667.

Differential Revision: https://reviews.llvm.org/D105668

compiler-rt/lib/hwasan/hwasan_fuchsia.cpp

@@ -172,6 +172,10 @@ void HwasanTSDThreadInit() {}
 // function is unneeded.
 void InstallAtExitHandler() {}
 
+// TODO(fxbug.dev/81499): Once we finalize the tagged pointer ABI in zircon, we should come back
+// here and implement the appropriate check that TBI is enabled.
+void InitializeOsSupport() {}
+
 }  // namespace __hwasan
 
 extern "C" {