[Sanitizer] Make StackTrace::Unwind the only public way to unwind a stack trace.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@194196 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/msan/msan.h b/lib/msan/msan.h
index 51fa2eb..4e6c619 100644
--- a/lib/msan/msan.h
+++ b/lib/msan/msan.h
@@ -72,7 +72,7 @@
 void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin);
 
 void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp,
-                   bool fast);
+                   bool request_fast_unwind);
 
 void ReportUMR(StackTrace *stack, u32 origin);
 void ReportExpectedUMRNotFound(StackTrace *stack);