tsan: remove DontDumpShadow from Go build

[dvyukov]

Summary

DontDumpShadow is used only in InitializeShadowMemory which is Go-only.

Depends on D110263.

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

 namespace __tsan {
 
 static const char kShadowMemoryMappingWarning[] =
     "FATAL: %s can not madvise shadow region [%zx, %zx] with %s (errno: %d)\n";
 static const char kShadowMemoryMappingHint[] =
     "HINT: if %s is not supported in your environment, you may set "
     "TSAN_OPTIONS=%s=0\n";
 
+#  if !SANITIZER_GO
 static void DontDumpShadow(uptr addr, uptr size) {
   if (common_flags()->use_madv_dontdump)
     if (!DontDumpShadowMemory(addr, size)) {
       Printf(kShadowMemoryMappingWarning, SanitizerToolName, addr, addr + size,
              "MADV_DONTDUMP", errno);
       Printf(kShadowMemoryMappingHint, "MADV_DONTDUMP", "use_madv_dontdump");
       Die();
     }
 }
 
-#if !SANITIZER_GO
 void InitializeShadowMemory() {
   // Map memory shadow.
   if (!MmapFixedSuperNoReserve(ShadowBeg(), ShadowEnd() - ShadowBeg(),
                                "shadow")) {
     Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
     Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
     Die();
   }