Swift Calling Convention: swiftcc for ARM.

Differential Revision: http://reviews.llvm.org/D18769

llvm-svn: 265482
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index bc7cf9c..6c09a24 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -430,6 +430,7 @@
 "``swiftcc``" - This calling convention is used for Swift language.
     - On X86-64 RCX and R8 are available for additional integer returns, and
       XMM2 and XMM3 are available for additional FP/vector returns.
+    - On iOS platforms, we use AAPCS-VFP calling convention.
 "``cc <n>``" - Numbered convention
     Any calling convention may be specified by number, allowing
     target-specific calling conventions to be used. Target specific