Swift Calling Convention: add swiftcc.

Differential Revision: http://reviews.llvm.org/D17863

llvm-svn: 265480
diff --git a/llvm/lib/Target/X86/X86FastISel.cpp b/llvm/lib/Target/X86/X86FastISel.cpp
index 40e1c2f..c5ba8d4 100644
--- a/llvm/lib/Target/X86/X86FastISel.cpp
+++ b/llvm/lib/Target/X86/X86FastISel.cpp
@@ -2852,6 +2852,7 @@
   case CallingConv::C:
   case CallingConv::Fast:
   case CallingConv::WebKit_JS:
+  case CallingConv::Swift:
   case CallingConv::X86_FastCall:
   case CallingConv::X86_64_Win64:
   case CallingConv::X86_64_SysV: