[TySan] Added a 'print_stacktrace' flag for more detailed errors

Author: gbMattN

compiler-rt/lib/tysan/tysan.cpp

@@ -198,7 +198,8 @@ static void reportError(void *Addr, int Size, tysan_type_descriptor *TD,
 
   if (pc) {
 
-    bool request_fast = StackTrace::WillUseFastUnwind(true);
+    bool request_fast =
+        StackTrace::WillUseFastUnwind(true) && !flags().print_stacktrace;
     BufferedStackTrace ST;
     ST.Unwind(kStackTraceMax, pc, bp, 0, 0, 0, request_fast);
     ST.Print();

compiler-rt/lib/tysan/tysan_flags.inc

@@ -15,3 +15,6 @@
 
 // TYSAN_FLAG(Type, Name, DefaultValue, Description)
 // See COMMON_FLAG in sanitizer_flags.inc for more details.
+
+TYSAN_FLAG(bool, print_stacktrace, false,
+           "Include full stacktrace into an error report")