Fix <rdar://problem/6512717> by correctly reading the right offset in the token data in PTHLexer::getSourceLocation().

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62725 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PTHLexer.cpp b/lib/Lex/PTHLexer.cpp
index aa59db5..9fa2bb2 100644
--- a/lib/Lex/PTHLexer.cpp
+++ b/lib/Lex/PTHLexer.cpp
@@ -324,7 +324,7 @@
   // handling a #included file.  Just read the necessary data from the token
   // data buffer to construct the SourceLocation object.
   // NOTE: This is a virtual function; hence it is defined out-of-line.
-  const unsigned char *OffsetPtr = CurPtr + (1 + 1 + 3);
+  const unsigned char *OffsetPtr = CurPtr + (DISK_TOKEN_SIZE - 4);
   uint32_t Offset = Read32(OffsetPtr);
   return FileStartLoc.getFileLocWithOffset(Offset);
 }