Add support for a chain of stat caches in the FileManager, rather than
only supporting a single stat cache. The immediate benefit of this
change is that we can now generate a PCH/AST file when including
another PCH file; in the future, the chain of stat caches will likely
be useful with multiple levels of PCH files.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84263 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PTHLexer.cpp b/lib/Lex/PTHLexer.cpp
index 36ace8b..f804f82 100644
--- a/lib/Lex/PTHLexer.cpp
+++ b/lib/Lex/PTHLexer.cpp
@@ -679,7 +679,8 @@
     CacheTy::iterator I = Cache.find(path);
 
     // If we don't get a hit in the PTH file just forward to 'stat'.
-    if (I == Cache.end()) return ::stat(path, buf);
+    if (I == Cache.end()) 
+      return StatSysCallCache::stat(path, buf);
 
     const PTHStatData& Data = *I;