Add support for the 'Q' constraint.

Fixes rdar://9866494


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136523 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 903efd7..46b4299 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -7596,6 +7596,9 @@
     case 'x': return C_RegisterClass;
     case 't': return C_RegisterClass;
     case 'j': return C_Other; // Constant for movw.
+      // An address with a single base register. Due to the way we
+      // currently handle addresses it is the same as an 'r' memory constraint.
+    case 'Q': return C_Memory;
     }
   } else if (Constraint.size() == 2) {
     switch (Constraint[0]) {