New local GCC patch for CAN_SANITIZE_UB ifdef.

2018-10-31  Martin Liska  <mliska@suse.cz>

	* ubsan/ubsan_platform.h: Add ifndef as we define it with
	-DCAN_SANITIZE_UB CFLAGS.

From-SVN: r265669

libsanitizer/ChangeLog

 2018-10-31  Martin Liska  <mliska@suse.cz>
 
+	* ubsan/ubsan_platform.h: Add ifndef as we define it with
+	-DCAN_SANITIZE_UB CFLAGS.
+
+2018-10-31  Martin Liska  <mliska@suse.cz>
+
 	* asan/asan_mapping.h: Revert shadow memory offset to 1 << 41.
 
 2018-10-31  Martin Liska  <mliska@suse.cz>

libsanitizer/ubsan/ubsan_platform.h

@@ -11,6 +11,7 @@
 #ifndef UBSAN_PLATFORM_H
 #define UBSAN_PLATFORM_H
 
+#ifndef CAN_SANITIZE_UB
 // Other platforms should be easy to add, and probably work as-is.
 #if defined(__linux__) || defined(__FreeBSD__) || defined(__APPLE__) ||        \
     defined(__NetBSD__) || defined(__OpenBSD__) || \
@@ -20,5 +21,6 @@
 #else
 # define CAN_SANITIZE_UB 0
 #endif
+#endif //CAN_SANITIZE_UB
 
 #endif