[PATCH] Prologue support

[Peter Collingbourne]

LGTM

Do you have commit access?

As I mentioned, this will require a trivial change to Clang (`s/setPrefixData/setPrologueData/` in `lib/CodeGen/CodeGenFunction.cpp`).

================
Comment at: docs/BitCodeFormat.rst:796
@@ +795,3 @@
+* *prologue*: If non-zero, the value index of the prologue data for this function,
+  plus 1.
+
----------------
Nit: these should use the same identifiers and be in the same order as the record spec above.

http://reviews.llvm.org/D6454