[sanitizer] Revert D38706

[cryptoad]

Summary

D38706 breaks tsan and the nolibc build.
Reverting while working on a fix.

lib/sanitizer_common/CMakeLists.txt

 # Build system for the common Sanitizer runtime support library components.
 # These components are shared between AddressSanitizer and ThreadSanitizer.
 
 set(SANITIZER_SOURCES_NOTERMINATION
   sanitizer_allocator.cc
-  sanitizer_allocator_checks.cc
   sanitizer_common.cc
   sanitizer_deadlock_detector1.cc
   sanitizer_deadlock_detector2.cc
   sanitizer_errno.cc
   sanitizer_file.cc
   sanitizer_flags.cc
   sanitizer_flag_parser.cc
   sanitizer_fuchsia.cc

lib/sanitizer_common/sanitizer_allocator_checks.h

 // Various checks shared between ThreadSanitizer, MemorySanitizer, etc. memory
 // allocators.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef SANITIZER_ALLOCATOR_CHECKS_H
 #define SANITIZER_ALLOCATOR_CHECKS_H
 
+#include "sanitizer_errno.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_common.h"
 #include "sanitizer_platform.h"
 
 namespace __sanitizer {
 
-// The following is defined in a separate compilation unit to avoid pulling in
-// sanitizer_errno.h in this header, which leads to conflicts when other system
-// headers include errno.h. This is usually the result of an unlikely event,
-// and as such we do not care as much about having it inlined.
-void SetErrnoToENOMEM();
-
 // A common errno setting logic shared by almost all sanitizer allocator APIs.
 INLINE void *SetErrnoOnNull(void *ptr) {
   if (UNLIKELY(!ptr))
-    SetErrnoToENOMEM();
+    errno = errno_ENOMEM;
   return ptr;
 }
 
 // In case of the check failure, the caller of the following Check... functions
 // should "return POLICY::OnBadRequest();" where POLICY is the current allocator
 // failure handling policy.
 
 // Checks aligned_alloc() parameters, verifies that the alignment is a power of

lib/sanitizer_common/sanitizer_allocator_checks.cc

-//===-- sanitizer_allocator_checks.cc ---------------------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// Various checks shared between ThreadSanitizer, MemorySanitizer, etc. memory
-// allocators.
-//
-//===----------------------------------------------------------------------===//
-
-#include "sanitizer_errno.h"
-
-namespace __sanitizer {
-
-void SetErrnoToENOMEM() {
-  errno = errno_ENOMEM;
-}
-
-} // namespace __sanitizer