[asan] Fix windows build.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@185917 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/asan/asan_interceptors.cc b/lib/asan/asan_interceptors.cc
index 374344f..b9b722e 100644
--- a/lib/asan/asan_interceptors.cc
+++ b/lib/asan/asan_interceptors.cc
@@ -123,8 +123,12 @@
 
 #define COMMON_SYSCALL_PRE_READ_RANGE(p, s) ASAN_READ_RANGE(p, s)
 #define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) ASAN_WRITE_RANGE(p, s)
-#define COMMON_SYSCALL_POST_READ_RANGE(p, s)
-#define COMMON_SYSCALL_POST_WRITE_RANGE(p, s)
+#define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
+  do {                                       \
+  } while (false)
+#define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
+  do {                                        \
+  } while (false)
 #include "sanitizer_common/sanitizer_common_syscalls.inc"
 
 static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) {