Revert "tsan: turn off COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED"

[dvyukov]

Summary

This reverts commit 5ec832269eedeeddcf00d34efd7272a107e2c7c1.

It broke a number of bots, e.g.:
https://lab.llvm.org/buildbot/#/builders/52/builds/11811

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

 #elif defined(__mips__)
 const int SA_SIGINFO = 8;
 const int SIG_SETMASK = 3;
 #else
 const int SA_SIGINFO = 4;
 const int SIG_SETMASK = 2;
 #endif
 
-// All tsan interceptors check for initialization and/or initialize things
-// as necessary lazily, so we can pretend everything is initialized in this
-// check to avoid double-checking for initialization (this is only necessary for
-// sanitizers that don't handle initialization on common grounds).
-#define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED false
+#define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED \
+  (!cur_thread_init()->is_inited)
 
 namespace __tsan {
 struct SignalDesc {
   bool armed;
   __sanitizer_siginfo siginfo;
   ucontext_t ctx;
 };