[PATCH] Refactor the code in clang to find a file in a PATH like environment variable into a helper function

[Hans Wennborg]

lgtm

================
Comment at: lib/Support/Process.cpp:74
@@ +73,3 @@
+                                             const std::string& FileName)
+{
+  Optional<std::string> FoundPath;
----------------
Nit: The curly should go on the previous line.

================
Comment at: lib/Support/Process.cpp:77
@@ +76,3 @@
+  Optional<std::string> OptPath = Process::GetEnv(EnvName);
+  if (!OptPath.hasValue())
+    return FoundPath;
----------------
I guess we can drop hasValue() here since Optional has its bool operator.

http://reviews.llvm.org/D4201