It turns out that the testcase in question uncovered subreg-handling bug.
Add assert in asmprinter to catch such cases and xfail the tests.
PR is to be filled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86375 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmPrinter/ARMMCInstLower.cpp b/lib/Target/ARM/AsmPrinter/ARMMCInstLower.cpp
index 8686961..c49fee3 100644
--- a/lib/Target/ARM/AsmPrinter/ARMMCInstLower.cpp
+++ b/lib/Target/ARM/AsmPrinter/ARMMCInstLower.cpp
@@ -137,6 +137,7 @@
     case MachineOperand::MO_Register:
       // Ignore all implicit register operands.
       if (MO.isImplicit()) continue;
+      assert(!MO.getSubReg() && "Subregs should be eliminated!");
       MCOp = MCOperand::CreateReg(MO.getReg());
       break;
     case MachineOperand::MO_Immediate: