Remove a duplicate declaration which broke the compiler-rt build

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/branches/release_34@197381 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/sanitizer_common/sanitizer_stacktrace.cc b/lib/sanitizer_common/sanitizer_stacktrace.cc
index de16bec..70ce26b 100644
--- a/lib/sanitizer_common/sanitizer_stacktrace.cc
+++ b/lib/sanitizer_common/sanitizer_stacktrace.cc
@@ -158,14 +158,6 @@
   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.