Add support for the X86 'l' constraint.

Fixes PR10149 and rdar://9738585

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134648 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 4f8b90f..01cea3b 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -12592,6 +12592,7 @@
     case 'y':
     case 'x':
     case 'Y':
+    case 'l':
       return C_RegisterClass;
     case 'a':
     case 'b':