[Statepoints] Split the calling convention and statepoint flags operand to STATEPOINT into two separate operands.

Differential Revision: http://reviews.llvm.org/D9623

llvm-svn: 237166
diff --git a/llvm/docs/Statepoints.rst b/llvm/docs/Statepoints.rst
index c381c3e..d657629 100644
--- a/llvm/docs/Statepoints.rst
+++ b/llvm/docs/Statepoints.rst
@@ -483,6 +483,12 @@
 
 Each statepoint generates the following Locations:
 
+* Constant which describes the calling convention of the call target. This
+  constant is a valid :ref:`calling convention identifier <callingconv>` for
+  the version of LLVM used to generate the stackmap. No additional compatibility
+  guarantees are made for this constant over what LLVM provides elsewhere w.r.t.
+  these identifiers.
+* Constant which describes the flags passed to the statepoint intrinsic
 * Constant which describes number of following deopt *Locations* (not
   operands)
 * Variable number of Locations, one for each deopt parameter listed in