Fix LTO builds with xcode 4.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132132 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index 19f57cf..c4ef57c 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1588,8 +1588,18 @@
   while (!Stream.AtEndOfStream()) {
     unsigned Code = Stream.ReadCode();
 
-    if (Code != bitc::ENTER_SUBBLOCK)
+    if (Code != bitc::ENTER_SUBBLOCK) {
+
+      // The ranlib in xcode 4 will align archive members by appending newlines to the
+      // end of them. If this file size is a multiple of 4 but not 8, we have to read and
+      // ignore these final 4 bytes :-(
+      if (Stream.GetAbbrevIDWidth() == 2 && Code == 2 &&
+          Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
+	  Stream.AtEndOfStream())
+        return false;
+
       return Error("Invalid record at top-level");
+    }
 
     unsigned BlockID = Stream.ReadSubBlockID();