[asan] add asan option log_path=PATH to let users redirect asan reports to a file PATH.PID instead of stderr

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@163872 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/sanitizer/common_interface_defs.h b/include/sanitizer/common_interface_defs.h
index f76462c..1aa4f0b 100644
--- a/include/sanitizer/common_interface_defs.h
+++ b/include/sanitizer/common_interface_defs.h
@@ -53,4 +53,10 @@
 
 }  // namespace __sanitizer
 
+extern "C" {
+  // Tell the tools to write their reports to "path.<pid>" instead of stderr.
+  void __sanitizer_set_report_path(const char *path)
+      SANITIZER_INTERFACE_ATTRIBUTE;
+}  // extern "C"
+
 #endif  // SANITIZER_COMMON_INTERFACE_DEFS_H