Merging r196809:

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r196809 | rsmith | 2013-12-09 11:52:39 -0800 (Mon, 09 Dec 2013) | 2 lines

Unbreak build by adding an implementation of PopStackFrames function.

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llvm-svn: 197010

compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cc

@@ -158,6 +158,14 @@ static bool MatchPc(uptr cur_pc, uptr trace_pc, uptr threshold) {
   return cur_pc - trace_pc <= threshold || trace_pc - cur_pc <= threshold;
 }
 
+void StackTrace::PopStackFrames(uptr count) {
+  CHECK(count < size);
+  size -= count;
+  for (uptr i = 0; i < size; ++i) {
+    trace[i] = trace[i + count];
+  }
+}
+
 uptr StackTrace::LocatePcInTrace(uptr pc) {
   // Use threshold to find PC in stack trace, as PC we want to unwind from may
   // slightly differ from return address in the actual unwinded stack trace.