Don't tip-to around BitstreamReader::JumpToBit jumping to the end of the stream. LLVM has been updated to allow this

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69146 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index 69745ce..ad3c2e5 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -889,18 +889,15 @@
   /// then restores it when destroyed.
   struct VISIBILITY_HIDDEN SavedStreamPosition {
     explicit SavedStreamPosition(llvm::BitstreamReader &Stream)
-      : Stream(Stream), Offset(Stream.GetCurrentBitNo()),
-        EndOfStream(Stream.AtEndOfStream()){ }
+      : Stream(Stream), Offset(Stream.GetCurrentBitNo()) { }
 
     ~SavedStreamPosition() {
-      if (!EndOfStream) 
-        Stream.JumpToBit(Offset);
+      Stream.JumpToBit(Offset);
     }
 
   private:
     llvm::BitstreamReader &Stream;
     uint64_t Offset;
-    bool EndOfStream;
   };
 }